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doc-exports/docs/ddm/umn/CLASS.TXT.json
Ru, Li Yi 4b09a03a51 ddm_umn 
Reviewed-by: Wagner, Fabian <fabian.wagner@t-systems.com>
Co-authored-by: Ru, Li Yi <liyiru7@huawei.com>
Co-committed-by: Ru, Li Yi <liyiru7@huawei.com>
2024-04-11 11:39:26 +00:00

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[
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Service Overview",
"uri":"ddm_01_0000.html",
"doc_type":"usermanual",
"p_code":"",
"code":"1"
},
{
"desc":"Distributed Database Middleware (DDM) is a MySQL-compatible, distributed middleware service designed for relational databases. It can resolve distributed scaling issues t",
"product_code":"ddm",
"title":"Overview",
"uri":"ddm_01_0001.html",
"doc_type":"usermanual",
"p_code":"1",
"code":"2"
},
{
"desc":"A data node is the minimum management unit of DDM. Each data node represents an independently running database, and it may be an RDS for MySQL or GaussDB(for MySQL) insta",
"product_code":"ddm",
"title":"Basic Concepts",
"uri":"ddm_01_0018.html",
"doc_type":"usermanual",
"p_code":"1",
"code":"3"
},
{
"desc":"DDM supports a variety of functions, including horizontal sharding, shard configuration, highly compatible SQL syntax, read/write splitting, and global sequence.",
"product_code":"ddm",
"title":"Core Functions",
"uri":"ddm_01_0016.html",
"doc_type":"usermanual",
"p_code":"1",
"code":"4"
},
{
"desc":"General-enhanced DDM instances use Intel® Xeon® Scalable processors. Working in high-performance networks, these DDM instances can offer high and stable computing perform",
"product_code":"ddm",
"title":"Product Specifications",
"uri":"ddm_01_0017.html",
"doc_type":"usermanual",
"p_code":"1",
"code":"5"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Usage Constraints",
"uri":"ddm_01_0003.html",
"doc_type":"usermanual",
"p_code":"1",
"code":"6"
},
{
"desc":"Restrictions on network access are as follows:The data nodes and ECSs running your applications must be in the same VPC as your DDM instance.To access DDM from your compu",
"product_code":"ddm",
"title":"Network Access",
"uri":"ddm_01_0004.html",
"doc_type":"usermanual",
"p_code":"6",
"code":"7"
},
{
"desc":"Constraints on data nodes are as follows:Data nodes can be only RDS for MySQL and GaussDB(for MySQL) instances of versions 5.7 and 8.0.DDM cannot connect to MySQL instanc",
"product_code":"ddm",
"title":"Data Nodes",
"uri":"ddm_01_0005.html",
"doc_type":"usermanual",
"p_code":"6",
"code":"8"
},
{
"desc":"Stored proceduresTriggersViewsEventsUser-defined functionsForeign key reference and associationFull-text indexes and SPACE functionsTemporary tablesCompound statements su",
"product_code":"ddm",
"title":"Unsupported Features and Limitations",
"uri":"ddm_01_0174.html",
"doc_type":"usermanual",
"p_code":"6",
"code":"9"
},
{
"desc":"Pay attention to the following when you use DDM:Do not connect to any data node for data operations to avoid deleting by mistake system catalogs or metadata.Do not clear ",
"product_code":"ddm",
"title":"High-risk Operations",
"uri":"ddm_01_0175.html",
"doc_type":"usermanual",
"p_code":"6",
"code":"10"
},
{
"desc":"The combination of a region and an availability zone (AZ) identifies the location of a data center. You can create resources in a specific AZ in a region.A region is a ge",
"product_code":"ddm",
"title":"Regions and AZs",
"uri":"ddm_01_0007.html",
"doc_type":"usermanual",
"p_code":"1",
"code":"11"
},
{
"desc":"As an OLTP-oriented service, DDM allows you to access distributed relational databases across a variety of industries.",
"product_code":"ddm",
"title":"Application Scenarios",
"uri":"ddm_01_0002.html",
"doc_type":"usermanual",
"p_code":"1",
"code":"12"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Getting Started",
"uri":"ddm_02_0001.html",
"doc_type":"usermanual",
"p_code":"",
"code":"13"
},
{
"desc":"This section describes how to associate a DDM instance with a data node (RDS for MySQL instance).Step 1: Create a DDM Instance and an RDS for MySQL InstanceStep 2: Create",
"product_code":"ddm",
"title":"Overview",
"uri":"ddm_01_0020.html",
"doc_type":"usermanual",
"p_code":"13",
"code":"14"
},
{
"desc":"The default database port is 5066 and can be changed after a DDM instance is created.For details, see Changing a Database Port.For details about how to create an RDS for ",
"product_code":"ddm",
"title":"Step 1: Create a DDM Instance and an RDS for MySQL Instance",
"uri":"ddm_06_0002.html",
"doc_type":"usermanual",
"p_code":"13",
"code":"15"
},
{
"desc":"Required permissions: SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, RELOAD, PROCESS, REFERENCES, INDEX, ALTER, SHOW DATABASES, CREATE TEMPORARY TABLES, LOCK TABLES, EXECU",
"product_code":"ddm",
"title":"Step 2: Create a Schema and Associate It with an RDS for MySQL Instance",
"uri":"ddm_02_0013.html",
"doc_type":"usermanual",
"p_code":"13",
"code":"16"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Step 3: Create a DDM Account",
"uri":"ddm_02_0000.html",
"doc_type":"usermanual",
"p_code":"13",
"code":"17"
},
{
"desc":"After you create a DDM instance, you can log in to it using a client such as Navicat, or connect to the required schema in the instance using the CLI or JDBC driver.This ",
"product_code":"ddm",
"title":"Step 4: Log In to the DDM Schema",
"uri":"ddm_02_0005.html",
"doc_type":"usermanual",
"p_code":"13",
"code":"18"
},
{
"desc":"Distributed Database Middleware (DDM) is a MySQL-compatible, distributed middleware service designed for relational databases. It can resolve distributed scaling issues t",
"product_code":"ddm",
"title":"Function Overview",
"uri":"ddm_03_0053.html",
"doc_type":"usermanual",
"p_code":"",
"code":"19"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Permissions Management",
"uri":"ddm_05_0000.html",
"doc_type":"usermanual",
"p_code":"",
"code":"20"
},
{
"desc":"To create a schema, import schema information, or configure shards, you can use the administrator account of data nodes or create a database account with the following pe",
"product_code":"ddm",
"title":"Database Accounts and Permissions",
"uri":"ddm_05_0021.html",
"doc_type":"usermanual",
"p_code":"20",
"code":"21"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Instance Management",
"uri":"ddm_06_0001.html",
"doc_type":"usermanual",
"p_code":"",
"code":"22"
},
{
"desc":"You have logged in to the DDM console.",
"product_code":"ddm",
"title":"Creating a DDM Instance",
"uri":"ddm_06_0132.html",
"doc_type":"usermanual",
"p_code":"22",
"code":"23"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Splitting Read-only and Read-Write Services",
"uri":"ddm_06_0025.html",
"doc_type":"usermanual",
"p_code":"22",
"code":"24"
},
{
"desc":"DDM provides read-only service isolation by grouping nodes of a DDM instance to provide physically separated compute and storage resources.DDM provides two types of node ",
"product_code":"ddm",
"title":"What Is Read-only Service Isolation?",
"uri":"ddm_06_0026.html",
"doc_type":"usermanual",
"p_code":"24",
"code":"25"
},
{
"desc":"One DDM instance supports multiple read-only groups. Each group contains at least 2 nodes, and each instance contains up to 32 nodes.One node belongs to only one group, a",
"product_code":"ddm",
"title":"How Are Read-only Services Split from Read-Write Services",
"uri":"ddm_06_0027.html",
"doc_type":"usermanual",
"p_code":"24",
"code":"26"
},
{
"desc":"You have logged in to the DDM console.The DDM instance is in the Running state.Change node class during off-peak hours because services will be interrupted for a while du",
"product_code":"ddm",
"title":"Changing Class of a DDM Node",
"uri":"ddm_06_0003.html",
"doc_type":"usermanual",
"p_code":"22",
"code":"27"
},
{
"desc":"As service data increases, you can scale out a DDM instance by adding nodes to improve service stability.Scale out your DDM instance during off-peak hours.Make sure that ",
"product_code":"ddm",
"title":"Scaling Out a DDM Instance",
"uri":"ddm_06_0011.html",
"doc_type":"usermanual",
"p_code":"22",
"code":"28"
},
{
"desc":"This section describes how to scale in a DDM instance as service data volume decreases.Scale in your DDM instance during off-peak hours.Make sure that the associated data",
"product_code":"ddm",
"title":"Scaling In a DDM Instance",
"uri":"ddm_06_0014.html",
"doc_type":"usermanual",
"p_code":"22",
"code":"29"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Restarting a DDM Instance",
"uri":"ddm_06_0004.html",
"doc_type":"usermanual",
"p_code":"22",
"code":"30"
},
{
"desc":"You may need to restart an instance to perform maintenance.The DDM instance is not available during restart, and the restart operation cannot be undone. Exercise caution ",
"product_code":"ddm",
"title":"Restarting a DDM Instance",
"uri":"ddm_06_0028.html",
"doc_type":"usermanual",
"p_code":"30",
"code":"31"
},
{
"desc":"You can restart a single node of your DDM instance.An instance is not available when one of its nodes is being restarted. The restart operation cannot be undone. Exercise",
"product_code":"ddm",
"title":"Restarting a Node",
"uri":"ddm_06_0029.html",
"doc_type":"usermanual",
"p_code":"30",
"code":"32"
},
{
"desc":"You can delete instances that are no longer needed.Deleted instances cannot be recovered. Exercise caution when performing this operation.Deleting a DDM instance will not",
"product_code":"ddm",
"title":"Deleting a DDM Instance",
"uri":"ddm_06_0005.html",
"doc_type":"usermanual",
"p_code":"22",
"code":"33"
},
{
"desc":"Configure parameters of a DDM instance based on your needs to keep the instance running well.There is a DDM instance available and running normally.By default, DDM allows",
"product_code":"ddm",
"title":"Modifying Parameters of a DDM Instance",
"uri":"ddm_03_0058.html",
"doc_type":"usermanual",
"p_code":"22",
"code":"34"
},
{
"desc":"You have logged in to the DDM console.The Change Parameter Template dialog box is displayed.",
"product_code":"ddm",
"title":"Changing a Parameter Template",
"uri":"ddm_06_0020.html",
"doc_type":"usermanual",
"p_code":"22",
"code":"35"
},
{
"desc":"DDM allows you to create an administrator account for your instance. This account has the superuser permissions to modify permissions of accounts displayed on the Account",
"product_code":"ddm",
"title":"Administrator Account",
"uri":"ddm_06_0021.html",
"doc_type":"usermanual",
"p_code":"22",
"code":"36"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Connection Management",
"uri":"ddm_06_0040.html",
"doc_type":"usermanual",
"p_code":"",
"code":"37"
},
{
"desc":"DDM supports load balancing by default, but some regions may not support. If an application accesses DDM using a private IP address, there are no traffic restrictions. To",
"product_code":"ddm",
"title":"Configuring Access Control",
"uri":"ddm_06_0035.html",
"doc_type":"usermanual",
"p_code":"37",
"code":"38"
},
{
"desc":"DDM allows you to change the database port of a DDM instance. After the port is changed, the instance will restart.For DDM instances, the database port number ranges from",
"product_code":"ddm",
"title":"Changing a Database Port",
"uri":"ddm_06_0036.html",
"doc_type":"usermanual",
"p_code":"37",
"code":"39"
},
{
"desc":"DDM allows you to change the security group of a DDM instance.Changing the security group may disconnect the DDM instance from its associated data nodes.Specify a new sec",
"product_code":"ddm",
"title":"Changing the Security Group of a DDM Instance",
"uri":"ddm_06_0039.html",
"doc_type":"usermanual",
"p_code":"37",
"code":"40"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Parameter Template Management",
"uri":"ddm_05_0005.html",
"doc_type":"usermanual",
"p_code":"",
"code":"41"
},
{
"desc":"A database parameter template acts as a container for parameter configurations that can be applied to one or more DDM instances. You can manage configurations of a DDM in",
"product_code":"ddm",
"title":"Creating a Parameter Template",
"uri":"ddm_05_0006.html",
"doc_type":"usermanual",
"p_code":"41",
"code":"42"
},
{
"desc":"To improve performance of a DDM instance, you can modify parameters in custom parameter templates based on service requirements.You cannot change parameter values in defa",
"product_code":"ddm",
"title":"Editing a Parameter Template",
"uri":"ddm_05_0007.html",
"doc_type":"usermanual",
"p_code":"41",
"code":"43"
},
{
"desc":"You can apply different parameter templates to the same DDM instance to view impacts on parameter settings of the instance.You can compare different custom parameter temp",
"product_code":"ddm",
"title":"Comparing Two Parameter Templates",
"uri":"ddm_05_0009.html",
"doc_type":"usermanual",
"p_code":"41",
"code":"44"
},
{
"desc":"You can view parameters of a DDM instance and change history of custom templates.An exported or custom parameter template has initially a blank change history.You can vie",
"product_code":"ddm",
"title":"Viewing Parameter Change History",
"uri":"ddm_05_0010.html",
"doc_type":"usermanual",
"p_code":"41",
"code":"45"
},
{
"desc":"You can replicate a parameter template you have created. When you have already created a parameter template and want to provide most of its custom parameters and values i",
"product_code":"ddm",
"title":"Replicating a Parameter Template",
"uri":"ddm_05_0011.html",
"doc_type":"usermanual",
"p_code":"41",
"code":"46"
},
{
"desc":"After you create a parameter template and modify parameters in it based on service requirements, you can apply it to your DDM instances.To apply a default template, click",
"product_code":"ddm",
"title":"Applying a Parameter Template",
"uri":"ddm_05_0013.html",
"doc_type":"usermanual",
"p_code":"41",
"code":"47"
},
{
"desc":"After a parameter template is applied to DDM instances, you can view its application records.You can view the name or ID of the DDM instance to which the parameter templa",
"product_code":"ddm",
"title":"Viewing Application Records of a Parameter Template",
"uri":"ddm_05_0014.html",
"doc_type":"usermanual",
"p_code":"41",
"code":"48"
},
{
"desc":"You can modify the description of a parameter template that you have created.You cannot modify the description of any default parameter template.The description contains ",
"product_code":"ddm",
"title":"Modifying the Description of a Parameter Template",
"uri":"ddm_05_0015.html",
"doc_type":"usermanual",
"p_code":"41",
"code":"49"
},
{
"desc":"You can delete custom parameter templates that will not be used any more.Deleted parameter templates cannot be recovered. Exercise caution when performing this operation.",
"product_code":"ddm",
"title":"Deleting a Parameter Template",
"uri":"ddm_05_0016.html",
"doc_type":"usermanual",
"p_code":"41",
"code":"50"
},
{
"desc":"You can view the progress and results of asynchronous tasks on the Task Center page.The following tasks can be viewed:Creating a DDM InstanceDeleting a DDM instanceChangi",
"product_code":"ddm",
"title":"Task Center",
"uri":"ddm_09_0002.html",
"doc_type":"usermanual",
"p_code":"",
"code":"51"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Schema Management",
"uri":"ddm_03_0006.html",
"doc_type":"usermanual",
"p_code":"",
"code":"52"
},
{
"desc":"You have logged in to the DDM console.The DDM instance is in the Running state.Do not modify or delete the internal accounts (DDMRW*, DDMR*, and DDMREP*) created on data ",
"product_code":"ddm",
"title":"Creating a Schema",
"uri":"ddm_06_0006.html",
"doc_type":"usermanual",
"p_code":"52",
"code":"53"
},
{
"desc":"When you deploy DR or migrate data across regions, you can export schema information from source DDM instances. The export information includes schema information and sha",
"product_code":"ddm",
"title":"Exporting Schema Information",
"uri":"ddm_06_0015.html",
"doc_type":"usermanual",
"p_code":"52",
"code":"54"
},
{
"desc":"When you deploy DR or migrate data across regions, you can import schema information in destination DDM instances. The imported information includes schema information an",
"product_code":"ddm",
"title":"Importing Schema Information",
"uri":"ddm_06_0007.html",
"doc_type":"usermanual",
"p_code":"52",
"code":"55"
},
{
"desc":"You have logged in to the DDM console.You have created a schema.Deleted schemas cannot be recovered. Exercise caution when performing this operation.Deleted schemas canno",
"product_code":"ddm",
"title":"Deleting a Schema",
"uri":"ddm_03_0008.html",
"doc_type":"usermanual",
"p_code":"52",
"code":"56"
},
{
"desc":"Configure a blacklist and add those statements to it to prevent the system executing some SQL statements.You have logged in to the DDM console.A DDM instance is running p",
"product_code":"ddm",
"title":"Configuring the SQL Blacklist",
"uri":"ddm_03_0100.html",
"doc_type":"usermanual",
"p_code":"52",
"code":"57"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Shard Configuration",
"uri":"ddm_03_0131.html",
"doc_type":"usermanual",
"p_code":"",
"code":"58"
},
{
"desc":"Shard configuration is a core function of DDM. With this function, you can increase data nodes or shards to improve database storage and concurrency as services grow. Sha",
"product_code":"ddm",
"title":"Overview and Application Scenarios",
"uri":"ddm_03_0068.html",
"doc_type":"usermanual",
"p_code":"58",
"code":"59"
},
{
"desc":"Before changing shards, you need to carry out a preliminary evaluation and determine the number of new shards, whether to scale up the current DDM node class, and the num",
"product_code":"ddm",
"title":"Assessment",
"uri":"ddm_03_0069.html",
"doc_type":"usermanual",
"p_code":"58",
"code":"60"
},
{
"desc":"Check items in the table below one day before performing a shard configuration task.The shard configuration fails due to table structure inconsistency.Solution: Execute C",
"product_code":"ddm",
"title":"Pre-check",
"uri":"ddm_03_0070.html",
"doc_type":"usermanual",
"p_code":"58",
"code":"61"
},
{
"desc":"This section uses an RDS for MySQL instance as an example to describe how to configure shards for a schema.There is a DDM instance with available schemas.There is an RDS ",
"product_code":"ddm",
"title":"Operation Guide",
"uri":"ddm_03_0071.html",
"doc_type":"usermanual",
"p_code":"58",
"code":"62"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Data Node Management",
"uri":"ddm_10_1000.html",
"doc_type":"usermanual",
"p_code":"",
"code":"63"
},
{
"desc":"Managing data nodes is managing RDS for MySQL or GaussDB(for MySQL) instances that are associated with your DDM instance. You can view the instance status, storage, class",
"product_code":"ddm",
"title":"Overview",
"uri":"ddm_10_1001.html",
"doc_type":"usermanual",
"p_code":"63",
"code":"64"
},
{
"desc":"You have logged in to the DDM console.After you change your data nodes, for example, adding or deleting a read replica, changing the connection address, port number, or s",
"product_code":"ddm",
"title":"Synchronizing Data Node Information",
"uri":"ddm_10_1003.html",
"doc_type":"usermanual",
"p_code":"63",
"code":"65"
},
{
"desc":"If one DDM instance is associated with multiple data nodes, you can synchronize read weight settings of the first data node to other data nodes.You have logged in to the ",
"product_code":"ddm",
"title":"Configuring Read Weights",
"uri":"ddm_10_1002.html",
"doc_type":"usermanual",
"p_code":"63",
"code":"66"
},
{
"desc":"Read/write splitting offloads read requests from primary instances to read replicas on a data node at a ratio, improving processing of read/write transactions. This funct",
"product_code":"ddm",
"title":"Splitting Read and Write Requests",
"uri":"ddm_06_0012.html",
"doc_type":"usermanual",
"p_code":"63",
"code":"67"
},
{
"desc":"You have logged in to the DDM console.If you want to deploy a DDM instance across regions for DR, use DRS to migrate service data and then reload table data after the mig",
"product_code":"ddm",
"title":"Reloading Table Data",
"uri":"ddm_03_0059.html",
"doc_type":"usermanual",
"p_code":"63",
"code":"68"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Account Management",
"uri":"ddm_05_0001.html",
"doc_type":"usermanual",
"p_code":"",
"code":"69"
},
{
"desc":"You have logged in to the DDM console.There are schemas available in the DDM instance that you want to create an account for.",
"product_code":"ddm",
"title":"Creating an Account",
"uri":"ddm_05_0002.html",
"doc_type":"usermanual",
"p_code":"69",
"code":"70"
},
{
"desc":"You have logged in to the DDM console.",
"product_code":"ddm",
"title":"Modifying an Account",
"uri":"ddm_05_0133.html",
"doc_type":"usermanual",
"p_code":"69",
"code":"71"
},
{
"desc":"You have logged in to the DDM console.Deleted accounts cannot be recovered. Exercise caution when performing this operation.",
"product_code":"ddm",
"title":"Deleting an Account",
"uri":"ddm_05_0134.html",
"doc_type":"usermanual",
"p_code":"69",
"code":"72"
},
{
"desc":"You have logged in to the DDM console.Resetting the DDM account password is a high-risk operation. Ensure that you have the IAM permission to modify DDM accounts.",
"product_code":"ddm",
"title":"Resetting the Password of an Account",
"uri":"ddm_05_0008.html",
"doc_type":"usermanual",
"p_code":"69",
"code":"73"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Backups and Restorations",
"uri":"ddm_03_0067.html",
"doc_type":"usermanual",
"p_code":"",
"code":"74"
},
{
"desc":"DDM allows you to restore data from the current instance to any point in time using an existing backup. This is a good choice for routine service backup and restoration.T",
"product_code":"ddm",
"title":"Restoring Data to a New Instance",
"uri":"ddm_06_0016.html",
"doc_type":"usermanual",
"p_code":"74",
"code":"75"
},
{
"desc":"DDM automatically backs up DDM instance metadata at 02:00 UTC+00:00 every day and retains the backup data for 30 days. Metadata backup is also triggered by key operations",
"product_code":"ddm",
"title":"Restoring Metadata",
"uri":"ddm_06_0017.html",
"doc_type":"usermanual",
"p_code":"74",
"code":"76"
},
{
"desc":"DDM provides a Slow Queries function that sorts out the same type of slow SQL statements within a specified period of time by SQL template. You can specify a time range, ",
"product_code":"ddm",
"title":"Slow Queries",
"uri":"ddm_13_0001.html",
"doc_type":"usermanual",
"p_code":"",
"code":"77"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Monitoring Management",
"uri":"ddm_03_0050.html",
"doc_type":"usermanual",
"p_code":"",
"code":"78"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Supported Metrics",
"uri":"ddm_16_0001.html",
"doc_type":"usermanual",
"p_code":"78",
"code":"79"
},
{
"desc":"This section describes metrics reported by DDM to Cloud Eye, metric namespaces, and dimensions. You can use APIs provided by Cloud Eye to query the metric information gen",
"product_code":"ddm",
"title":"DDM Instance Metrics",
"uri":"ddm_03_0051.html",
"doc_type":"usermanual",
"p_code":"79",
"code":"80"
},
{
"desc":"If load balancing is enabled for your DDM instance, you can view network metrics in the following table. If load balancing is not enabled, you do not have the permissions",
"product_code":"ddm",
"title":"Network Metrics",
"uri":"ddm_03_0054.html",
"doc_type":"usermanual",
"p_code":"79",
"code":"81"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Viewing Metrics",
"uri":"ddm_16_0002.html",
"doc_type":"usermanual",
"p_code":"78",
"code":"82"
},
{
"desc":"Cloud Eye monitors the running status of DDM instances. You can view instance monitoring metrics on the DDM console.Monitored data requires a period of time for transmiss",
"product_code":"ddm",
"title":"Viewing Instance Metrics",
"uri":"ddm_03_0052.html",
"doc_type":"usermanual",
"p_code":"82",
"code":"83"
},
{
"desc":"The DDM console supports monitoring and management of network metrics.If load balancing is enabled for your DDM instance, you can view network metrics. If load balancing ",
"product_code":"ddm",
"title":"Viewing Network Metrics",
"uri":"ddm_16_0003.html",
"doc_type":"usermanual",
"p_code":"82",
"code":"84"
},
{
"desc":"Tag Management Service (TMS) enables you to use tags on the console to manage resources. TMS works with other cloud services to manage tags. TMS manages tags globally. Ot",
"product_code":"ddm",
"title":"Tags",
"uri":"ddm_06_1000.html",
"doc_type":"usermanual",
"p_code":"",
"code":"85"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Auditing",
"uri":"ddm_11_0001.html",
"doc_type":"usermanual",
"p_code":"",
"code":"86"
},
{
"desc":"Cloud Trace Service (CTS) records operations related to DDM for further query, audit, and backtrack.",
"product_code":"ddm",
"title":"Key Operations Recorded by CTS",
"uri":"ddm_11_0002.html",
"doc_type":"usermanual",
"p_code":"86",
"code":"87"
},
{
"desc":"After CTS is enabled, the tracker starts recording operations on cloud resources. Operation records for the last 7 days are stored on the CTS console.This section describ",
"product_code":"ddm",
"title":"Querying Traces",
"uri":"ddm_11_0003.html",
"doc_type":"usermanual",
"p_code":"86",
"code":"88"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"SQL Syntax",
"uri":"ddm_08_0001.html",
"doc_type":"usermanual",
"p_code":"",
"code":"89"
},
{
"desc":"DDM is compatible with the MySQL license and syntax, but the use of SQL statements is limited due to differences between distributed databases and single-node databases.B",
"product_code":"ddm",
"title":"Introduction",
"uri":"ddm_03_0062.html",
"doc_type":"usermanual",
"p_code":"89",
"code":"90"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"DDL",
"uri":"ddm_08_0003.html",
"doc_type":"usermanual",
"p_code":"89",
"code":"91"
},
{
"desc":"DDM supports common DDL operations, such as creating databases, creating tables, and modifying table structure, but the implementation method is different from that in co",
"product_code":"ddm",
"title":"Overview",
"uri":"ddm_12_0006.html",
"doc_type":"usermanual",
"p_code":"91",
"code":"92"
},
{
"desc":"Do not create tables whose names start with _ddm. DDM manages such tables as internal tables by defaultSharded tables do not support globally unique indexes. If the uniqu",
"product_code":"ddm",
"title":"Creating a Table",
"uri":"ddm_08_0029.html",
"doc_type":"usermanual",
"p_code":"91",
"code":"93"
},
{
"desc":"DDM supports database sharding, table sharding, and a variety of sharding algorithms.Database and table sharding keys cannot be left blank.In DDM, sharding of a logical t",
"product_code":"ddm",
"title":"Sharding Algorithm Overview",
"uri":"ddm_03_0038.html",
"doc_type":"usermanual",
"p_code":"91",
"code":"94"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Sharding Algorithms",
"uri":"ddm_10_0018.html",
"doc_type":"usermanual",
"p_code":"91",
"code":"95"
},
{
"desc":"This algorithm applies if you want to route data to different database shards by user ID or order ID.The sharding key must be CHAR, VARCHAR, INT, INTEGER, BIGINT, MEDIUMI",
"product_code":"ddm",
"title":"MOD_HASH",
"uri":"ddm_10_0002.html",
"doc_type":"usermanual",
"p_code":"95",
"code":"96"
},
{
"desc":"This algorithm applies if you want to route data to different database shards by user ID or order ID.The sharding key must be CHAR, VARCHAR, INT, INTEGER, BIGINT, MEDIUMI",
"product_code":"ddm",
"title":"MOD_HASH_CI",
"uri":"ddm_12_0007.html",
"doc_type":"usermanual",
"p_code":"95",
"code":"97"
},
{
"desc":"This algorithm applies if a large difference appears in high-digit part but a small difference in low-digit part of sharding key values. Using this algorithm ensures unif",
"product_code":"ddm",
"title":"RIGHT_SHIFT",
"uri":"ddm_10_0004.html",
"doc_type":"usermanual",
"p_code":"95",
"code":"98"
},
{
"desc":"This algorithm applies if you want to shard data by month. One table shard for one month is recommended, and its name is the month number.The sharding key must be DATE, D",
"product_code":"ddm",
"title":"MM",
"uri":"ddm_10_0014.html",
"doc_type":"usermanual",
"p_code":"95",
"code":"99"
},
{
"desc":"This algorithm applies if you want to shard data by date. One table shard for one day is recommended, and its name is the day number.The sharding key must be DATE, DATETI",
"product_code":"ddm",
"title":"DD",
"uri":"ddm_10_0015.html",
"doc_type":"usermanual",
"p_code":"95",
"code":"100"
},
{
"desc":"This algorithm applies when you want to shard data by day in a week. One table shard for one weekday is recommended.The sharding key must be DATE, DATETIME, or TIMESTAMP.",
"product_code":"ddm",
"title":"WEEK",
"uri":"ddm_10_0017.html",
"doc_type":"usermanual",
"p_code":"95",
"code":"101"
},
{
"desc":"This algorithm applies when you want to shard data by day in a year. One table shard for one day (at most 366 days in a year) is recommended.The sharding key must be DATE",
"product_code":"ddm",
"title":"MMDD",
"uri":"ddm_10_0016.html",
"doc_type":"usermanual",
"p_code":"95",
"code":"102"
},
{
"desc":"This algorithm applies when data is routed to shards by year and month. You are advised to use this algorithm together with tbpartition YYYYMM(ShardKey).The sharding key ",
"product_code":"ddm",
"title":"YYYYMM",
"uri":"ddm_10_0006.html",
"doc_type":"usermanual",
"p_code":"95",
"code":"103"
},
{
"desc":"This algorithm applies when data is routed to shards by year and day. You are advised to use this algorithm together with tbpartition YYYYDD(ShardKey).The sharding key mu",
"product_code":"ddm",
"title":"YYYYDD",
"uri":"ddm_10_0007.html",
"doc_type":"usermanual",
"p_code":"95",
"code":"104"
},
{
"desc":"This algorithm applies when data is routed to shards by week. You are advised to use this algorithm together with tbpartition YYYYWEEK(ShardKey).The sharding key must be ",
"product_code":"ddm",
"title":"YYYYWEEK",
"uri":"ddm_10_0008.html",
"doc_type":"usermanual",
"p_code":"95",
"code":"105"
},
{
"desc":"This algorithm features even distribution of data and sharding tables. Arithmetic operators such as equality (=) and IN operators are often used in SQL queries.The shardi",
"product_code":"ddm",
"title":"HASH",
"uri":"ddm_10_0012.html",
"doc_type":"usermanual",
"p_code":"95",
"code":"106"
},
{
"desc":"This algorithm applies to routing data in different ranges to different shards. Less-than signs (<), greater-than signs (>), and BETWEEN ... AND ... are frequently used i",
"product_code":"ddm",
"title":"Range",
"uri":"ddm_10_0013.html",
"doc_type":"usermanual",
"p_code":"95",
"code":"107"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"DML",
"uri":"ddm_08_0004.html",
"doc_type":"usermanual",
"p_code":"89",
"code":"108"
},
{
"desc":"INSERT is used to insert data into database objects.INSERT DELAYED is not supported.Only INSERT statements that contain sharding fields are supported.PARTITION syntax is ",
"product_code":"ddm",
"title":"INSERT",
"uri":"ddm_08_0005.html",
"doc_type":"usermanual",
"p_code":"108",
"code":"109"
},
{
"desc":"REPLACE is used to insert rows into or replace rows in a table.PARTITION syntax is not supported.If an auto-increment table has no ID, you can insert a data record with a",
"product_code":"ddm",
"title":"REPLACE",
"uri":"ddm_08_0007.html",
"doc_type":"usermanual",
"p_code":"108",
"code":"110"
},
{
"desc":"DELETE is used to delete rows that meet conditions from a table.The WHERE clause does not support subqueries, including correlated and non-correlated subqueries.Data in r",
"product_code":"ddm",
"title":"DELETE",
"uri":"ddm_08_0008.html",
"doc_type":"usermanual",
"p_code":"108",
"code":"111"
},
{
"desc":"Subqueries are not supported, including correlated and non-correlated subqueries.Cross-shard subquery is not supported.The WHERE condition in the UPDATE statement does no",
"product_code":"ddm",
"title":"UPDATE",
"uri":"ddm_08_0009.html",
"doc_type":"usermanual",
"p_code":"108",
"code":"112"
},
{
"desc":"SELECT is generally used to query data in one or more tables.Supported syntaxSyntaxDescriptionselect_exprIndicates a column that you want to query.FROM table_referencesIn",
"product_code":"ddm",
"title":"SELECT",
"uri":"ddm_08_0006.html",
"doc_type":"usermanual",
"p_code":"108",
"code":"113"
},
{
"desc":"table_references:table_reference:table_factor:join_table:join_condition:SELECT STRAIGHT_JOIN and NATURAL JOIN are not supported.",
"product_code":"ddm",
"title":"SELECT JOIN Syntax",
"uri":"ddm_08_0010.html",
"doc_type":"usermanual",
"p_code":"108",
"code":"114"
},
{
"desc":"SELECT statements in UNION do not support duplicate column names.",
"product_code":"ddm",
"title":"SELECT UNION Syntax",
"uri":"ddm_08_0011.html",
"doc_type":"usermanual",
"p_code":"108",
"code":"115"
},
{
"desc":"ExampleSyntaxExampleSyntaxExampleSyntaxExampleEach derived table must have an alias.A derived table cannot be a correlated subquery.In some cases, correct results cannot ",
"product_code":"ddm",
"title":"SELECT Subquery Syntax",
"uri":"ddm_08_0012.html",
"doc_type":"usermanual",
"p_code":"108",
"code":"116"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Supported System Schema Queries",
"uri":"ddm_12_0100.html",
"doc_type":"usermanual",
"p_code":"108",
"code":"117"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Functions",
"uri":"ddm_03_0063.html",
"doc_type":"usermanual",
"p_code":"89",
"code":"118"
},
{
"desc":"DDM is compatible with the MySQL license and syntax, but the use of SQL statements is limited due to differences between distributed databases and single-node databases.T",
"product_code":"ddm",
"title":"Use Constraints",
"uri":"ddm_08_0013.html",
"doc_type":"usermanual",
"p_code":"89",
"code":"119"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Supported SQL Statements",
"uri":"ddm_08_0002.html",
"doc_type":"usermanual",
"p_code":"89",
"code":"120"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"CHECK TABLE",
"uri":"ddm_08_0014.html",
"doc_type":"usermanual",
"p_code":"120",
"code":"121"
},
{
"desc":"Purpose: To check DDL consistency of all logical tables in one schemaCommand Format:Command Output:The following output is returned if DDL check results of all logical ta",
"product_code":"ddm",
"title":"Checking DDL Consistency of Physical Tables in All Logical Tables",
"uri":"ddm_08_0021.html",
"doc_type":"usermanual",
"p_code":"121",
"code":"122"
},
{
"desc":"Purpose: To check DDL consistency of physical tables in a specific logical tableCommand Format:Command Output:If the returned result set is empty, DDL results of physical",
"product_code":"ddm",
"title":"Checking DDL Consistency of Physical Tables in One Logical Table",
"uri":"ddm_08_0022.html",
"doc_type":"usermanual",
"p_code":"121",
"code":"123"
},
{
"desc":"Command Format 1:show rule;It is used to view the sharding rule of each logical table in a certain schema.Command output:Command Format 2:show rule from<table_name>;It is",
"product_code":"ddm",
"title":"SHOW RULE",
"uri":"ddm_08_0015.html",
"doc_type":"usermanual",
"p_code":"120",
"code":"124"
},
{
"desc":"Command Format:show topology from<table_name>;It is used to view physical tables corresponding to a specified logical table.Output Details:RDS_instance_id: indicates the ",
"product_code":"ddm",
"title":"SHOW TOPOLOGY",
"uri":"ddm_08_0017.html",
"doc_type":"usermanual",
"p_code":"120",
"code":"125"
},
{
"desc":"Command Format:show data node;It is used to view data about database shards in the RDS instance.Output Details:RDS_instance_id: indicates the ID of the RDS instance.PHYSI",
"product_code":"ddm",
"title":"SHOW DATA NODE",
"uri":"ddm_08_0130.html",
"doc_type":"usermanual",
"p_code":"120",
"code":"126"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"TRUNCATE TABLE",
"uri":"ddm_08_0023.html",
"doc_type":"usermanual",
"p_code":"120",
"code":"127"
},
{
"desc":"Command Format:/*+db=<physical_db_name>*/ TRUNCATE TABLE<table_name>Description:Deleting data in physical tables corresponding to <table_name> in <physical_db_name> does ",
"product_code":"ddm",
"title":"HINT-DB",
"uri":"ddm_08_0024.html",
"doc_type":"usermanual",
"p_code":"127",
"code":"128"
},
{
"desc":"HINTs are instructions within a SQL statement that tell the optimizer to execute the statement in a flexible way. This section describes how to use HINT syntax to delete ",
"product_code":"ddm",
"title":"HINT-TABLE",
"uri":"ddm_08_0025.html",
"doc_type":"usermanual",
"p_code":"127",
"code":"129"
},
{
"desc":"Command Format:/*+db=<physical_db_name>,table=<physical_table_name>*/ TRUNCATE TABLE<table_name>Description:Deleting data in physical table <physical_table_name> in datab",
"product_code":"ddm",
"title":"HINT-DB/TABLE",
"uri":"ddm_08_0026.html",
"doc_type":"usermanual",
"p_code":"127",
"code":"130"
},
{
"desc":"Command Format:/*+ allow_alter_rerun=true*/<ALTER TABLE>Description:Using this hint ensures that commands can be repeatedly executed, and no error is reported. This hint ",
"product_code":"ddm",
"title":"HINT- ALLOW_ALTER_RERUN",
"uri":"ddm_08_0027.html",
"doc_type":"usermanual",
"p_code":"120",
"code":"131"
},
{
"desc":"LOAD DATA LOCAL INFILE '/data/data.txt' IGNORE INTO TABLE test CHARACTER SET 'utf8' FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '\"' LINES TERMINATED BY '\\n' (id, sid,",
"product_code":"ddm",
"title":"LOAD DATA",
"uri":"ddm_03_0031.html",
"doc_type":"usermanual",
"p_code":"120",
"code":"132"
},
{
"desc":"Command Format 1:show physical processlist;This command returns the processes that run on the associated RDS instance.Command Format 2:show physical processlist with in",
"product_code":"ddm",
"title":"SHOW PHYSICAL PROCESSLIST",
"uri":"ddm_08_0032.html",
"doc_type":"usermanual",
"p_code":"120",
"code":"133"
},
{
"desc":"DDM allows you to customize a hint to specify whether SQL statements are executed on the primary instance or its read replicas.The following hint formats are supported:Fo",
"product_code":"ddm",
"title":"Customized Hints for Read/Write Splitting",
"uri":"ddm_03_0034.html",
"doc_type":"usermanual",
"p_code":"120",
"code":"134"
},
{
"desc":"DDM allows you to configure a hint to control whether each SELECT statement skips the cached execution plan.The hint is in the format of /*!GAUSS:skip_plancache=flag*/.fl",
"product_code":"ddm",
"title":"Setting a Hint to Skip the Cached Execution Plan",
"uri":"ddm_03_0039.html",
"doc_type":"usermanual",
"p_code":"120",
"code":"135"
},
{
"desc":"Command Format:Description:Specify a shard by configuring <physical_db_name> and execute a SQL statement on the shard.Example:Restrictions:The hint is valid only for SELE",
"product_code":"ddm",
"title":"Specifying a Shard Using a Hint When Executing a SQL Statement",
"uri":"ddm_03_0040.html",
"doc_type":"usermanual",
"p_code":"120",
"code":"136"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Global Sequence",
"uri":"ddm_03_0030.html",
"doc_type":"usermanual",
"p_code":"89",
"code":"137"
},
{
"desc":"Global sequences are mainly database-based global sequences.The start auto-increment SN can be modified.Global sequence provides sequence numbers that are globally unique",
"product_code":"ddm",
"title":"Overview",
"uri":"ddm_12_0010.html",
"doc_type":"usermanual",
"p_code":"137",
"code":"138"
},
{
"desc":"NEXTVAL returns the next sequence number, and CURRVAL returns the current sequence number. nextval(n) returns n unique sequence numbers.nextval(n) can be used only in sel",
"product_code":"ddm",
"title":"Using NEXTVAL or CURRVAL to Query Global Sequence Numbers",
"uri":"ddm_03_0036.html",
"doc_type":"usermanual",
"p_code":"137",
"code":"139"
},
{
"desc":"You can use global sequences in INSERT or REPLACE statements to provide unique global sequence across schemas in a DDM instance. Generating sequence numbers with NEXTVAL ",
"product_code":"ddm",
"title":"Using Global Sequences in INSERT or REPLACE Statements",
"uri":"ddm_03_0037.html",
"doc_type":"usermanual",
"p_code":"137",
"code":"140"
},
{
"desc":"SHOW SyntaxSHOW COLUMNS SyntaxSHOW CREATE TABLE SyntaxSHOW TABLE STATUS SyntaxSHOW TABLES SyntaxSHOW DATABASESIf the required database is not found, check fine-grained pe",
"product_code":"ddm",
"title":"Database Management Syntax",
"uri":"ddm_03_0032.html",
"doc_type":"usermanual",
"p_code":"89",
"code":"141"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Advanced SQL Functions",
"uri":"ddm_03_0035.html",
"doc_type":"usermanual",
"p_code":"89",
"code":"142"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"FAQs",
"uri":"ddm_04_0001.html",
"doc_type":"usermanual",
"p_code":"",
"code":"143"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"General Questions",
"uri":"ddm_04_0066.html",
"doc_type":"usermanual",
"p_code":"143",
"code":"144"
},
{
"desc":"DDM instance faults do not affect data integrity.Service data is stored in shards of data nodes, but not on DDM.Configuration information of schemas and logical tables is",
"product_code":"ddm",
"title":"What High-Reliability Mechanisms Does DDM Provide?",
"uri":"ddm_04_0068.html",
"doc_type":"usermanual",
"p_code":"144",
"code":"145"
},
{
"desc":"DDM uses VPCs and security groups to ensure security of your instances. The following provides guidance for you on how to correctly configure a security group.Access to a",
"product_code":"ddm",
"title":"How Do I Select and Configure a Security Group?",
"uri":"ddm_04_0067.html",
"doc_type":"usermanual",
"p_code":"144",
"code":"146"
},
{
"desc":"No. Different data nodes associated with a DDM instance are independent of each other and cannot share data.",
"product_code":"ddm",
"title":"Can Data Nodes Associated with a DDM Instance Share Data?",
"uri":"ddm_12_0011.html",
"doc_type":"usermanual",
"p_code":"144",
"code":"147"
},
{
"desc":"Any data nodes can be associated with a DDM instance as long as they are:Running normallyIn the same VPC as the DDM instanceNot in use by other DDM instances",
"product_code":"ddm",
"title":"What Data Nodes Can Be Associated with a DDM Instance?",
"uri":"ddm_12_0012.html",
"doc_type":"usermanual",
"p_code":"144",
"code":"148"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"DDM Usage",
"uri":"ddm_04_0004.html",
"doc_type":"usermanual",
"p_code":"143",
"code":"149"
},
{
"desc":"When you access a DDM instance using the MySQL driver (JDBC) in load balancing mode, an infinite loop may occur during connection switchover, resulting in stack overflow.",
"product_code":"ddm",
"title":"What Do I Do If I Fail to Connect to a DDM Instance Using the JDBC Driver?",
"uri":"ddm_04_0008.html",
"doc_type":"usermanual",
"p_code":"149",
"code":"150"
},
{
"desc":"Currently, you cannot connect to DDM using JDBC driver 5.1.46. Versions 5.1.35 to 5.1.45 are recommended.JDBC driver download address:https://dev.mysql.com/downloads/conn",
"product_code":"ddm",
"title":"What Version and Parameters Should I Select?",
"uri":"ddm_04_0009.html",
"doc_type":"usermanual",
"p_code":"149",
"code":"151"
},
{
"desc":"The version of the mysqldump client may be inconsistent with that of the supported MySQL server, so exporting data from MySQL is slow.Using the same version of the mysqld",
"product_code":"ddm",
"title":"Why It Takes So Long Time to Export Data from MySQL Using mysqldump?",
"uri":"ddm_04_0013.html",
"doc_type":"usermanual",
"p_code":"149",
"code":"152"
},
{
"desc":"When you create a table in DDM, set the start value for automatic increment and ensure that the start value is greater than the maximum auto-increment value of imported d",
"product_code":"ddm",
"title":"What Do I Do If a Duplicate Primary Key Error Occurs When Data Is Imported into DDM?",
"uri":"ddm_04_0014.html",
"doc_type":"usermanual",
"p_code":"149",
"code":"153"
},
{
"desc":"Execute the following SQL statement to modify the start value of the auto-increment primary key so that the value is greater than the maximum value of primary keys in exi",
"product_code":"ddm",
"title":"What Should I Do If an Error Message Is Returned When I Specify an Auto-Increment Primary Key During Migration?",
"uri":"ddm_04_0035.html",
"doc_type":"usermanual",
"p_code":"149",
"code":"154"
},
{
"desc":"Adjust the SocketTimeOut value or leave this parameter blank. The default value is 0, indicating that the client is not disconnected.",
"product_code":"ddm",
"title":"What Do I Do If an Error Is Reported When Parameter Configuration Does Not Time Out?",
"uri":"ddm_04_0031.html",
"doc_type":"usermanual",
"p_code":"149",
"code":"155"
},
{
"desc":"After an RDS instance is associated with your schema, you cannot delete the instance directly. To delete it, you have to delete the schema first and then delete the insta",
"product_code":"ddm",
"title":"Which Should I Delete First, a Schema or its Associated RDS Instances?",
"uri":"ddm_04_0050.html",
"doc_type":"usermanual",
"p_code":"149",
"code":"156"
},
{
"desc":"If you do not need to delete the databases or accounts, you can manually delete them to free up space.",
"product_code":"ddm",
"title":"Can I Manually Delete Databases and Accounts Remained in Data Nodes After a Schema Is Deleted?",
"uri":"ddm_04_0051.html",
"doc_type":"usermanual",
"p_code":"149",
"code":"157"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"SQL Syntax",
"uri":"ddm_04_0046.html",
"doc_type":"usermanual",
"p_code":"143",
"code":"158"
},
{
"desc":"Yes. DDM supports distributed JOINs.Redundant fields are added during table design.Cross-shard JOIN is implemented by using broadcast tables, ER shards, and ShareJoin.Cur",
"product_code":"ddm",
"title":"Does DDM Support Distributed JOINs?",
"uri":"ddm_04_0015.html",
"doc_type":"usermanual",
"p_code":"158",
"code":"159"
},
{
"desc":"You are advised to use INNER instead of LEFT JOIN or RIGHT JOIN.When LEFT JOIN or RIGHT JOIN is used, ON is preferentially executed, and WHERE is executed at the end. The",
"product_code":"ddm",
"title":"How Do I Optimize SQL Statements?",
"uri":"ddm_04_0016.html",
"doc_type":"usermanual",
"p_code":"158",
"code":"160"
},
{
"desc":"Data type conversion is an advanced function. DDM will be gradually upgraded to be compatible with more SQL syntax. If necessary, submit a service ticket for processing.",
"product_code":"ddm",
"title":"Does DDM Support Forced Conversion of Data Types?",
"uri":"ddm_04_0019.html",
"doc_type":"usermanual",
"p_code":"158",
"code":"161"
},
{
"desc":"Split an INSERT statement into multiple small statements.",
"product_code":"ddm",
"title":"What Should I Do If an Error Is Reported When Multiple Data Records Are Inserted into Batches Using the INSERT Statement?",
"uri":"ddm_04_0036.html",
"doc_type":"usermanual",
"p_code":"158",
"code":"162"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"RDS-related Questions",
"uri":"ddm_04_0047.html",
"doc_type":"usermanual",
"p_code":"143",
"code":"163"
},
{
"desc":"DDM is case-insensitive to database names, table names, and column names by default.",
"product_code":"ddm",
"title":"Is the Name of a Database Table Case-Sensitive?",
"uri":"ddm_04_0048.html",
"doc_type":"usermanual",
"p_code":"163",
"code":"164"
},
{
"desc":"Table 1 lists risky operations on RDS for MySQL.",
"product_code":"ddm",
"title":"What Risky Operations on RDS for MySQL Will Affect DDM?",
"uri":"ddm_04_0025.html",
"doc_type":"usermanual",
"p_code":"163",
"code":"165"
},
{
"desc":"If there is already a primary key whose data type is a boundary value, in your DDM instance, duplicate primary keys will be reported when you insert a data record that is",
"product_code":"ddm",
"title":"How Do I Handle Data with Duplicate Primary Keys in a Table?",
"uri":"ddm_04_0028.html",
"doc_type":"usermanual",
"p_code":"163",
"code":"166"
},
{
"desc":"After you connect to a DDM instance through the MySQL client, you can run command show full innodb status to query information about the associated RDS for MySQL instance",
"product_code":"ddm",
"title":"How Can I Query RDS for MySQL Information by Running Command show full innodb status?",
"uri":"ddm_04_0029.html",
"doc_type":"usermanual",
"p_code":"163",
"code":"167"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Connection Management",
"uri":"ddm_04_0097.html",
"doc_type":"usermanual",
"p_code":"143",
"code":"168"
},
{
"desc":"If the MySQL connection code is inconsistent with the actual one, garbled characters may be displayed during parsing on DDM.In this case, configure default-character-set=",
"product_code":"ddm",
"title":"How Can I Handle Garbled Characters Generated When I Connect a MySQL Instance to a DDM Instance?",
"uri":"ddm_04_0006.html",
"doc_type":"usermanual",
"p_code":"168",
"code":"169"
},
{
"desc":"HUAWEI CLOUD Help Center presents technical documents to help you quickly get started with HUAWEI CLOUD services. The technical documents include Service Overview, Price Details, Purchase Guide, User Guide, API Reference, Best Practices, FAQs, and Videos.",
"product_code":"ddm",
"title":"Change History",
"uri":"ddm_history_0003.html",
"doc_type":"usermanual",
"p_code":"",
"code":"170"
}
]
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