- About MogDB
- Quick Start
- Characteristic Description
- Overview
- High Performance
- CBO Optimizer
- LLVM
- Vectorized Engine
- Hybrid Row-Column Store
- Adaptive Compression
- Adaptive Two-phase Hash Aggregation
- SQL Bypass
- Kunpeng NUMA Architecture Optimization
- High Concurrency of Thread Pools
- SMP for Parallel Execution
- Xlog no Lock Flush
- Parallel Page-based Redo For Ustore
- Row-Store Execution to Vectorized Execution
- Astore Row Level Compression
- BTree Index Compression
- Tracing SQL Function
- Parallel Index Scan
- Parallel Query Optimization
- Enhancement of Tracing Backend Key Thread
- Ordering Operator Optimization
- OCK-accelerated Data Transmission
- OCK SCRLock Accelerate Distributed Lock
- Enhancement of WAL Redo Performance
- Enhancement of Dirty Pages Flushing Performance
- Sequential Scan Prefetch
- Ustore SMP Parallel Scanning
- High Availability (HA)
- Primary/Standby
- Logical Replication
- Logical Backup
- Physical Backup
- Automatic Job Retry upon Failure
- Ultimate RTO
- High Availability Based on the Paxos Protocol
- Cascaded Standby Server
- Delayed Replay
- Adding or Deleting a Standby Server
- Delaying Entering the Maximum Availability Mode
- Parallel Logical Decoding
- DCF
- CM(Cluster Manager)
- Global SysCache
- Using a Standby Node to Build a Standby Node
- Two City and Three Center DR
- CM Cluster Management Component Supporting Two Node Deployment
- Query of the Original DDL Statement for a View
- MogDB/CM/PTK Dual Network Segment Support
- Enhanced Efficiency of Logical Backup and Restore
- Maintainability
- Workload Diagnosis Report (WDR)
- Slow SQL Diagnosis
- Session Performance Diagnosis
- System KPI-aided Diagnosis
- Fault Diagnosis
- Extension Splitting
- Built-in Stack Tool
- SQL PATCH
- Lightweight Lock Export and Analysis
- DCF Module Tracing
- Error When Writing Illegal Characters
- Support For Pageinspect & Pagehack
- Autonomous Transaction Management View and Termination
- Corrupt Files Handling
- Compatibility
- Add %rowtype Attribute To The View
- Aggregate Functions Distinct Performance Optimization
- Aggregate Functions Support Keep Clause
- Aggregate Functions Support Scenario Extensions
- Compatible With MySQL Alias Support For Single Quotes
- current_date/current_time Keywords As Field Name
- Custom Type Array
- For Update Support Outer Join
- MogDB Supports Insert All
- Oracle DBLink Syntax Compatibility
- Remove Type Conversion Hint When Creating PACKAGE/FUNCTION/PROCEDURE
- Support Bypass Method When Merge Into Hit Index
- Support For Adding Nocopy Attributes To Procedure And Function Parameters
- Support For Passing The Count Attribute Of An Array As A Parameter Of The Array Extend
- Support Q Quote Escape Character
- Support Subtracting Two Date Types To Return Numeric Type
- Support table()
- Support To Keep The Same Name After The End With Oracle
- Support Where Current Of
- Support For Constants In Package As Default Values
- Support PLPGSQL subtype
- Support Synonym Calls Without Parentheses For Function Without Parameters
- Support For dbms_utility.format_error_backtrace
- Support for PIVOT and UNPIVOT Syntax
- Mod Function Compatibility
- Support for Nesting of Aggregate Functions
- ORDER BY/GROUP BY Scenario Expansion
- Support for Modifying Table Log Properties After Table Creation
- Support for INSERT ON CONFLICT Clause
- Support for AUTHID CURRENT_USER
- Support for Stored Procedure OUT Parameters in PBE Mode
- Database Security
- Access Control Model
- Separation of Control and Access Permissions
- Database Encryption Authentication
- Data Encryption and Storage
- Database Audit
- Network Communication Security
- Resource Label
- Unified Audit
- Dynamic Data Anonymization
- Row-Level Access Control
- Password Strength Verification
- Equality Query in a Fully-encrypted Database
- Ledger Database Mechanism
- Transparent Data Encryption
- Enterprise-Level Features
- Support for Functions and Stored Procedures
- SQL Hints
- Full-Text Indexing
- Copy Interface for Error Tolerance
- Partitioning
- Support for Advanced Analysis Functions
- Materialized View
- HyperLogLog
- Creating an Index Online
- Autonomous Transaction
- Global Temporary Table
- Pseudocolumn ROWNUM
- Stored Procedure Debugging
- JDBC Client Load Balancing and Read/Write Isolation
- In-place Update Storage Engine
- Publication-Subscription
- Foreign Key Lock Enhancement
- Data Compression in OLTP Scenarios
- Transaction Async Submit
- Index Creation Parallel Control
- Dynamic Partition Pruning
- COPY Import Optimization
- SQL Running Status Observation
- BRIN Index
- BLOOM Index
- Event Trigger
- Scrollable Cursor Support for Reverse Retrieval
- Support for Pruning Subquery Projection Columns
- Pruning ORDER BY in Subqueries
- Automatic Creation of Indexes Supporting Fuzzy Matching
- Support for Importing and Exporting Specific Objects
- Application Development Interfaces
- AI Capabilities
- Middleware
- Workload Management
- Installation Guide
- Upgrade Guide
- Administrator Guide
- Localization
- Routine Maintenance
- Starting and Stopping MogDB
- Using the gsql Client for Connection
- Routine Maintenance
- Checking OS Parameters
- Checking MogDB Health Status
- Checking Database Performance
- Checking and Deleting Logs
- Checking Time Consistency
- Checking The Number of Application Connections
- Routinely Maintaining Tables
- Routinely Recreating an Index
- Exporting and Viewing the WDR
- Data Security Maintenance Suggestions
- Slow SQL Diagnosis
- Log Reference
- Primary and Standby Management
- Column-store Tables Management
- Backup and Restoration
- Database Deployment Solutions
- Importing and Exporting Data
- High Available Guide
- AI Features Guide
- AI4DB: Autonomous Database O&M
- DBMind Mode
- Components that Support DBMind
- AI Sub-functions of the DBMind
- ABO Optimizer
- DB4AI: Database-driven AI
- AI4DB: Autonomous Database O&M
- Security Guide
- Developer Guide
- Application Development Guide
- Development Specifications
- Development Based on JDBC
- JDBC Package, Driver Class, and Environment Class
- Development Process
- Loading the Driver
- Connecting to a Database
- Connecting to the Database (Using SSL)
- Connecting to the Database (Using UDS)
- Running SQL Statements
- Processing Data in a Result Set
- Closing a Connection
- Managing Logs
- Example: Common Operations
- Example: Retrying SQL Queries for Applications
- Example: Importing and Exporting Data Through Local Files
- Example 2: Migrating Data from a MY Database to MogDB
- Example: Logic Replication Code
- Example: Parameters for Connecting to the Database in Different Scenarios
- Example: JDBC Primary/Standby Cluster Load Balancing
- JDBC API Reference
- java.sql.Connection
- java.sql.CallableStatement
- java.sql.DatabaseMetaData
- java.sql.Driver
- java.sql.PreparedStatement
- java.sql.ResultSet
- java.sql.ResultSetMetaData
- java.sql.Statement
- javax.sql.ConnectionPoolDataSource
- javax.sql.DataSource
- javax.sql.PooledConnection
- javax.naming.Context
- javax.naming.spi.InitialContextFactory
- CopyManager
- JDBC-based Common Parameter Reference
- JDBC Release Notes
- Development Based on ODBC
- Development Based on libpq
- Psycopg2-Based Development
- Commissioning
- Stored Procedure
- User Defined Functions
- PL/pgSQL-SQL Procedural Language
- Scheduled Jobs
- Autonomous Transaction
- Logical Replication
- Extension
- MySQL Compatibility Description
- Dolphin Extension
- Dolphin Overview
- Dolphin Installation
- Dolphin Restrictions
- Dolphin Syntax
- SQL Reference
- Keywords
- Data Types
- Functions and Operators
- Assignment Operators
- Character Processing Functions and Operators
- Arithmetic Functions and Operators
- Dolphin Lock
- Date and Time Processing Functions and Operators
- Advisory Lock Functions
- Network Address Functions and Operators
- Conditional Expression Functions
- Aggregate Functions
- System Information Functions
- Logical Operators
- Bit String Functions and Operators
- JSON-JSONB Functions and Operators
- Type Conversion Functions
- Compatible Operators and Operations
- Comment Operators
- Expressions
- DDL Syntax
- DML Syntax
- DCL Syntax
- SQL Syntax
- ALTER DATABASE
- ALTER FUNCTION
- ALTER PROCEDURE
- ALTER SERVER
- ALTER TABLE
- ALTER TABLE PARTITION
- ALTER TABLESPACE
- ALTER VIEW
- ANALYZE | ANALYSE
- AST
- CHECKSUM TABLE
- CREATE DATABASE
- CREATE FUNCTION
- CREATE INDEX
- CREATE PROCEDURE
- CREATE SERVER
- CREATE TABLE
- CREATE TABLE AS
- CREATE TABLE PARTITION
- CREATE TABLESPACE
- CREATE TRIGGER
- CREATE VIEW
- DESCRIBE TABLE
- DO
- DROP DATABASE
- DROP INDEX
- DROP TABLESPACE
- EXECUTE
- EXPLAIN
- FLUSH BINARY LOGS
- GRANT
- GRANT/REVOKE PROXY
- INSERT
- KILL
- LOAD DATA
- OPTIMIZE TABLE
- PREPARE
- RENAME TABLE
- RENAME USER
- REVOKE
- SELECT
- SELECT HINT
- SET CHARSET
- SET PASSWORD
- SHOW CHARACTER SET
- SHOW COLLATION
- SHOW COLUMNS
- SHOW CREATE DATABASE
- SHOW CREATE FUNCTION
- SHOW CREATE PROCEDURE
- SHOW CREATE TABLE
- SHOW CREATE TRIGGER
- SHOW CREATE VIEW
- SHOW DATABASES
- SHOW FUNCTION STATUS
- SHOW GRANTS
- SHOW INDEX
- SHOW MASTER STATUS
- SHOW PLUGINS
- SHOW PRIVILEGES
- SHOW PROCEDURE STATUS
- SHOW PROCESSLIST
- SHOW SLAVE HOSTS
- SHOW STATUS
- SHOW TABLES
- SHOW TABLE STATUS
- SHOW TRIGGERS
- SHOW VARIABLES
- SHOW WARNINGS/ERRORS
- UPDATE
- USE db_name
- System Views
- GUC Parameters
- Resetting Parameters
- Stored Procedures
- Identifiers
- SQL Reference
- MySQL Syntax Compatibility Assessment Tool
- Dolphin Extension
- Materialized View
- Partition Management
- Application Development Guide
- Performance Tuning Guide
- Reference Guide
- System Catalogs and System Views
- Overview
- Querying a System Catalog
- System Catalogs
- GS_ASP
- GS_AUDITING_POLICY
- GS_AUDITING_POLICY_ACCESS
- GS_AUDITING_POLICY_FILTERS
- GS_AUDITING_POLICY_PRIVILEGES
- GS_CLIENT_GLOBAL_KEYS
- GS_CLIENT_GLOBAL_KEYS_ARGS
- GS_COLUMN_KEYS
- GS_COLUMN_KEYS_ARGS
- GS_DB_PRIVILEGE
- GS_ENCRYPTED_COLUMNS
- GS_ENCRYPTED_PROC
- GS_GLOBAL_CHAIN
- GS_GLOBAL_CONFIG
- GS_MASKING_POLICY
- GS_MASKING_POLICY_ACTIONS
- GS_MASKING_POLICY_FILTERS
- GS_MATVIEW
- GS_MATVIEW_DEPENDENCY
- GS_MODEL_WAREHOUSE
- GS_OPT_MODEL
- GS_PACKAGE
- GS_POLICY_LABEL
- GS_RECYCLEBIN
- GS_TXN_SNAPSHOT
- GS_UID
- GS_WLM_EC_OPERATOR_INFO
- GS_WLM_INSTANCE_HISTORY
- GS_WLM_OPERATOR_INFO
- GS_WLM_PLAN_ENCODING_TABLE
- GS_WLM_PLAN_OPERATOR_INFO
- GS_WLM_SESSION_QUERY_INFO_ALL
- GS_WLM_USER_RESOURCE_HISTORY
- PG_AGGREGATE
- PG_AM
- PG_AMOP
- PG_AMPROC
- PG_APP_WORKLOADGROUP_MAPPING
- PG_ATTRDEF
- PG_ATTRIBUTE
- PG_AUTH_HISTORY
- PG_AUTH_MEMBERS
- PG_AUTHID
- PG_CAST
- PG_CLASS
- PG_COLLATION
- PG_CONSTRAINT
- PG_CONVERSION
- PG_DATABASE
- PG_DB_ROLE_SETTING
- PG_DEFAULT_ACL
- PG_DEPEND
- PG_DESCRIPTION
- PG_DIRECTORY
- PG_ENUM
- PG_EVENT_TRIGGER
- PG_EXTENSION
- PG_EXTENSION_DATA_SOURCE
- PG_FOREIGN_DATA_WRAPPER
- PG_FOREIGN_SERVER
- PG_FOREIGN_TABLE
- PG_HASHBUCKET
- PG_INDEX
- PG_INHERITS
- PG_JOB
- PG_JOB_PROC
- PG_LANGUAGE
- PG_LARGEOBJECT
- PG_LARGEOBJECT_METADATA
- PG_NAMESPACE
- PG_OBJECT
- PG_OPCLASS
- PG_OPERATOR
- PG_OPFAMILY
- PG_PARTITION
- PG_PLTEMPLATE
- PG_PROC
- PG_PUBLICATION
- PG_PUBLICATION_REL
- PG_RANGE
- PG_REPLICATION_ORIGIN
- PG_RESOURCE_POOL
- PG_REWRITE
- PG_RLSPOLICY
- PG_SECLABEL
- PG_SET
- PG_SHDEPEND
- PG_SHDESCRIPTION
- PG_SHSECLABEL
- PG_STATISTIC
- PG_STATISTIC_EXT
- PG_SUBSCRIPTION
- PG_SUBSCRIPTION_REL
- PG_SYNONYM
- PG_TABLESPACE
- PG_TRIGGER
- PG_TS_CONFIG
- PG_TS_CONFIG_MAP
- PG_TS_DICT
- PG_TS_PARSER
- PG_TS_TEMPLATE
- PG_TYPE
- PG_USER_MAPPING
- PG_USER_STATUS
- PG_WORKLOAD_GROUP
- PGXC_CLASS
- PGXC_GROUP
- PGXC_NODE
- PGXC_SLICE
- PLAN_TABLE_DATA
- STATEMENT_HISTORY
- System Views
- GET_GLOBAL_PREPARED_XACTS(Discarded)
- GS_ASYNC_SUBMIT_SESSIONS_STATUS
- GS_AUDITING
- GS_AUDITING_ACCESS
- GS_AUDITING_PRIVILEGE
- GS_CLUSTER_RESOURCE_INFO
- GS_COMPRESSION
- GS_DB_PRIVILEGES
- GS_FILE_STAT
- GS_GSC_MEMORY_DETAIL
- GS_INSTANCE_TIME
- GS_LABELS
- GS_LSC_MEMORY_DETAIL
- GS_MASKING
- GS_MATVIEWS
- GS_OS_RUN_INFO
- GS_REDO_STAT
- GS_SESSION_CPU_STATISTICS
- GS_SESSION_MEMORY
- GS_SESSION_MEMORY_CONTEXT
- GS_SESSION_MEMORY_DETAIL
- GS_SESSION_MEMORY_STATISTICS
- GS_SESSION_STAT
- GS_SESSION_TIME
- GS_SHARED_MEMORY_DETAIL
- GS_SQL_COUNT
- GS_STAT_SESSION_CU
- GS_THREAD_MEMORY_CONTEXT
- GS_TOTAL_MEMORY_DETAIL
- GS_WLM_CGROUP_INFO
- GS_WLM_EC_OPERATOR_STATISTICS
- GS_WLM_OPERATOR_HISTORY
- GS_WLM_OPERATOR_STATISTICS
- GS_WLM_PLAN_OPERATOR_HISTORY
- GS_WLM_REBUILD_USER_RESOURCE_POOL
- GS_WLM_RESOURCE_POOL
- GS_WLM_SESSION_HISTORY
- GS_WLM_SESSION_INFO
- GS_WLM_SESSION_INFO_ALL
- GS_WLM_SESSION_STATISTICS
- GS_WLM_USER_INFO
- IOS_STATUS
- MPP_TABLES
- PG_AVAILABLE_EXTENSION_VERSIONS
- PG_AVAILABLE_EXTENSIONS
- PG_COMM_DELAY
- PG_COMM_RECV_STREAM
- PG_COMM_SEND_STREAM
- PG_COMM_STATUS
- PG_CONTROL_GROUP_CONFIG
- PG_CURSORS
- PG_EXT_STATS
- PG_GET_INVALID_BACKENDS
- PG_GET_SENDERS_CATCHUP_TIME
- PG_GROUP
- PG_GTT_ATTACHED_PIDS
- PG_GTT_RELSTATS
- PG_GTT_STATS
- PG_INDEXES
- PG_LOCKS
- PG_NODE_ENV
- PG_OS_THREADS
- PG_PREPARED_STATEMENTS
- PG_PREPARED_XACTS
- PG_PUBLICATION_TABLES
- PG_REPLICATION_ORIGIN_STATUS
- PG_REPLICATION_SLOTS
- PG_RLSPOLICIES
- PG_ROLES
- PG_RULES
- PG_RUNNING_XACTS
- PG_SECLABELS
- PG_SESSION_IOSTAT
- PG_SESSION_WLMSTAT
- PG_SETTINGS
- PG_SHADOW
- PG_STAT_ACTIVITY
- PG_STAT_ACTIVITY_NG
- PG_STAT_ALL_INDEXES
- PG_STAT_ALL_TABLES
- PG_STAT_BAD_BLOCK
- PG_STAT_BGWRITER
- PG_STAT_DATABASE
- PG_STAT_DATABASE_CONFLICTS
- PG_STAT_REPLICATION
- PG_STAT_SUBSCRIPTION
- PG_STAT_SYS_INDEXES
- PG_STAT_SYS_TABLES
- PG_STAT_USER_FUNCTIONS
- PG_STAT_USER_INDEXES
- PG_STAT_USER_TABLES
- PG_STAT_XACT_ALL_TABLES
- PG_STAT_XACT_SYS_TABLES
- PG_STAT_XACT_USER_FUNCTIONS
- PG_STAT_XACT_USER_TABLES
- PG_STATIO_ALL_INDEXES
- PG_STATIO_ALL_SEQUENCES
- PG_STATIO_ALL_TABLES
- PG_STATIO_SYS_INDEXES
- PG_STATIO_SYS_SEQUENCES
- PG_STATIO_SYS_TABLES
- PG_STATIO_USER_INDEXES
- PG_STATIO_USER_SEQUENCES
- PG_STATIO_USER_TABLES
- PG_STATS
- PG_TABLES
- PG_TDE_INFO
- PG_THREAD_WAIT_STATUS
- PG_TIMEZONE_ABBREVS
- PG_TIMEZONE_NAMES
- PG_TOTAL_MEMORY_DETAIL
- PG_TOTAL_USER_RESOURCE_INFO
- PG_TOTAL_USER_RESOURCE_INFO_OID
- PG_USER
- PG_USER_MAPPINGS
- PG_VARIABLE_INFO
- PG_VIEWS
- PG_WLM_STATISTICS
- PGXC_PREPARED_XACTS
- PLAN_TABLE
- PATCH_INFORMATION_TABLE
- Functions and Operators
- Logical Operators
- Comparison Operators
- Character Processing Functions and Operators
- Binary String Functions and Operators
- Bit String Functions and Operators
- Mode Matching Operators
- Mathematical Functions and Operators
- Date and Time Processing Functions and Operators
- Type Conversion Functions
- Geometric Functions and Operators
- Network Address Functions and Operators
- Text Search Functions and Operators
- JSON/JSONB Functions and Operators
- HLL Functions and Operators
- SEQUENCE Functions
- Array Functions and Operators
- Range Functions and Operators
- Aggregate Functions
- Window Functions(Analysis Functions)
- Security Functions
- Ledger Database Functions
- Encrypted Equality Functions
- Set Returning Functions
- Conditional Expression Functions
- System Information Functions
- System Administration Functions
- Configuration Settings Functions
- Universal File Access Functions
- Server Signal Functions
- Backup and Restoration Control Functions
- Snapshot Synchronization Functions
- Database Object Functions
- Advisory Lock Functions
- Logical Replication Functions
- Segment-Page Storage Functions
- Other Functions
- Undo System Functions
- Row-store Compression System Functions
- Statistics Information Functions
- Trigger Functions
- Event Trigger Functions
- Hash Function
- Prompt Message Function
- Global Temporary Table Functions
- Fault Injection System Function
- AI Feature Functions
- Dynamic Data Masking Functions
- Other System Functions
- Internal Functions
- Global SysCache Feature Functions
- Data Damage Detection and Repair Functions
- XML Functions
- Obsolete Functions
- Supported Data Types
- SQL Syntax
- ABORT
- ALTER AGGREGATE
- ALTER AUDIT POLICY
- ALTER DATABASE
- ALTER DATA SOURCE
- ALTER DEFAULT PRIVILEGES
- ALTER DIRECTORY
- ALTER EVENT
- ALTER EVENT TRIGGER
- ALTER EXTENSION
- ALTER FOREIGN DATA WRAPPER
- ALTER FOREIGN TABLE
- ALTER FUNCTION
- ALTER GLOBAL CONFIGURATION
- ALTER GROUP
- ALTER INDEX
- ALTER LANGUAGE
- ALTER LARGE OBJECT
- ALTER MASKING POLICY
- ALTER MATERIALIZED VIEW
- ALTER OPERATOR
- ALTER PACKAGE
- ALTER PROCEDURE
- ALTER PUBLICATION
- ALTER RESOURCE LABEL
- ALTER RESOURCE POOL
- ALTER ROLE
- ALTER ROW LEVEL SECURITY POLICY
- ALTER RULE
- ALTER SCHEMA
- ALTER SEQUENCE
- ALTER SERVER
- ALTER SESSION
- ALTER SUBSCRIPTION
- ALTER SYNONYM
- ALTER SYSTEM KILL SESSION
- ALTER SYSTEM SET
- ALTER TABLE
- ALTER TABLE PARTITION
- ALTER TABLE SUBPARTITION
- ALTER TABLESPACE
- ALTER TEXT SEARCH CONFIGURATION
- ALTER TEXT SEARCH DICTIONARY
- ALTER TRIGGER
- ALTER TYPE
- ALTER USER
- ALTER USER MAPPING
- ALTER VIEW
- ANALYZE | ANALYSE
- BEGIN
- CALL
- CHECKPOINT
- CLEAN CONNECTION
- CLOSE
- CLUSTER
- COMMENT
- COMMIT | END
- COMMIT PREPARED
- CONNECT BY
- COPY
- CREATE AGGREGATE
- CREATE AUDIT POLICY
- CREATE CAST
- CREATE CLIENT MASTER KEY
- CREATE COLUMN ENCRYPTION KEY
- CREATE DATABASE
- CREATE DATA SOURCE
- CREATE DIRECTORY
- CREATE EVENT
- CREATE EVENT TRIGGER
- CREATE EXTENSION
- CREATE FOREIGN DATA WRAPPER
- CREATE FOREIGN TABLE
- CREATE FUNCTION
- CREATE GROUP
- CREATE INCREMENTAL MATERIALIZED VIEW
- CREATE INDEX
- CREATE LANGUAGE
- CREATE MASKING POLICY
- CREATE MATERIALIZED VIEW
- CREATE MODEL
- CREATE OPERATOR
- CREATE PACKAGE
- CREATE PROCEDURE
- CREATE PUBLICATION
- CREATE RESOURCE LABEL
- CREATE RESOURCE POOL
- CREATE ROLE
- CREATE ROW LEVEL SECURITY POLICY
- CREATE RULE
- CREATE SCHEMA
- CREATE SEQUENCE
- CREATE SERVER
- CREATE SUBSCRIPTION
- CREATE SYNONYM
- CREATE TABLE
- CREATE TABLE AS
- CREATE TABLE PARTITION
- CREATE TABLESPACE
- CREATE TABLE SUBPARTITION
- CREATE TEXT SEARCH CONFIGURATION
- CREATE TEXT SEARCH DICTIONARY
- CREATE TRIGGER
- CREATE TYPE
- CREATE USER
- CREATE USER MAPPING
- CREATE VIEW
- CREATE WEAK PASSWORD DICTIONARY
- CURSOR
- DEALLOCATE
- DECLARE
- DELETE
- DELIMITER
- DO
- DROP AGGREGATE
- DROP AUDIT POLICY
- DROP CAST
- DROP CLIENT MASTER KEY
- DROP COLUMN ENCRYPTION KEY
- DROP DATABASE
- DROP DATA SOURCE
- DROP DIRECTORY
- DROP EVENT
- DROP EVENT TRIGGER
- DROP EXTENSION
- DROP FOREIGN DATA WRAPPER
- DROP FOREIGN TABLE
- DROP FUNCTION
- DROP GLOBAL CONFIGURATION
- DROP GROUP
- DROP INDEX
- DROP LANGUAGE
- DROP MASKING POLICY
- DROP MATERIALIZED VIEW
- DROP MODEL
- DROP OPERATOR
- DROP OWNED
- DROP PACKAGE
- DROP PROCEDURE
- DROP PUBLICATION
- DROP RESOURCE LABEL
- DROP RESOURCE POOL
- DROP ROLE
- DROP ROW LEVEL SECURITY POLICY
- DROP RULE
- DROP SCHEMA
- DROP SEQUENCE
- DROP SERVER
- DROP SUBSCRIPTION
- DROP SYNONYM
- DROP TABLE
- DROP TABLESPACE
- DROP TEXT SEARCH CONFIGURATION
- DROP TEXT SEARCH DICTIONARY
- DROP TRIGGER
- DROP TYPE
- DROP USER
- DROP USER MAPPING
- DROP VIEW
- DROP WEAK PASSWORD DICTIONARY
- EXECUTE
- EXECUTE DIRECT
- EXPLAIN
- EXPLAIN PLAN
- FETCH
- GRANT
- INSERT
- LOCK
- MERGE INTO
- MOVE
- PREDICT BY
- PREPARE
- PREPARE TRANSACTION
- PURGE
- REASSIGN OWNED
- REFRESH INCREMENTAL MATERIALIZED VIEW
- REFRESH MATERIALIZED VIEW
- REINDEX
- RELEASE SAVEPOINT
- RESET
- REVOKE
- ROLLBACK
- ROLLBACK PREPARED
- ROLLBACK TO SAVEPOINT
- SAVEPOINT
- SELECT
- SELECT INTO
- SET
- SET CONSTRAINTS
- SET ROLE
- SET SESSION AUTHORIZATION
- SET TRANSACTION
- SHOW
- SHOW EVENTS
- SHRINK
- SHUTDOWN
- SNAPSHOT
- START TRANSACTION
- TIMECAPSULE TABLE
- TRUNCATE
- UPDATE
- VACUUM
- VALUES
- SQL Reference
- MogDB SQL
- Keywords
- Constant and Macro
- Expressions
- Type Conversion
- Full Text Search
- System Operation
- DDL Syntax Overview
- DML Syntax Overview
- DCL Syntax Overview
- Subquery
- LLVM
- Alias
- Lock
- Transaction
- Ordinary Table
- Partitioned Table
- Index
- Constraints
- Cursors
- Anonymous Block
- Trigger
- INSERT_RIGHT_REF_DEFAULT_VALUE
- Appendix
- GUC Parameters
- GUC Parameter Usage
- GUC Parameter List
- File Location
- Connection and Authentication
- Resource Consumption
- Write Ahead Log
- HA Replication
- Query Planning
- Error Reporting and Logging
- Alarm Detection
- Statistics During the Database Running
- Load Management
- Automatic Vacuuming
- Default Settings of Client Connection
- Lock Management
- Version and Platform Compatibility
- Faut Tolerance
- Connection Pool Parameters
- MogDB Transaction
- Replication Parameters of Two Database Instances
- Developer Options
- Auditing
- CM Parameters
- Backend Compression
- Upgrade Parameters
- Miscellaneous Parameters
- Wait Events
- Query
- System Performance Snapshot
- Security Configuration
- Global Temporary Table
- HyperLogLog
- Scheduled Task
- Thread Pool
- User-defined Functions
- Backup and Restoration
- DCF Parameters Settings
- Flashback
- Rollback Parameters
- Reserved Parameters
- AI Features
- Global SysCache Parameters
- Multi-Level Cache Management Parameters
- Resource Pooling Parameters
- Parameters Related to Efficient Data Compression Algorithms
- Writer Statement Parameters Supported by Standby Servers
- Data Import and Export
- Delimiter
- Appendix
- Schema
- Information Schema
- DBE_PERF
- OS
- Instance
- Memory
- File
- Object
- STAT_USER_TABLES
- SUMMARY_STAT_USER_TABLES
- GLOBAL_STAT_USER_TABLES
- STAT_USER_INDEXES
- SUMMARY_STAT_USER_INDEXES
- GLOBAL_STAT_USER_INDEXES
- STAT_SYS_TABLES
- SUMMARY_STAT_SYS_TABLES
- GLOBAL_STAT_SYS_TABLES
- STAT_SYS_INDEXES
- SUMMARY_STAT_SYS_INDEXES
- GLOBAL_STAT_SYS_INDEXES
- STAT_ALL_TABLES
- SUMMARY_STAT_ALL_TABLES
- GLOBAL_STAT_ALL_TABLES
- STAT_ALL_INDEXES
- SUMMARY_STAT_ALL_INDEXES
- GLOBAL_STAT_ALL_INDEXES
- STAT_DATABASE
- SUMMARY_STAT_DATABASE
- GLOBAL_STAT_DATABASE
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gs_checkos
Context
gs_checkos helps you check the OS version information, control parameters, and disk configurations, and configure control parameters, I/O parameters, network parameters, and THP services.
Prerequisites
- The hardware and network are working properly.
- The trust relationship of user root among the hosts is normal.
- Only user root is authorized to run the gs_checkos command.
NOTE: This tool cannot be invoked independently. For security purposes, it will be automatically deleted after the preinstallation is complete in enterprise-edition installation mode.
Syntax
-
Check OS information.
gs_checkos -i ITEM [-f HOSTFILE] [-h HOSTNAME] [-X XMLFILE] [--detail] [-o OUTPUT] [-l LOGFILE]
-
Display help information.
gs_checkos -? | --help
-
Display version information.
gs_checkos -V | --version
Parameter Description
-
-i
Specifies the number of a check item. The format is -i A, -i B1, -i A1 -i A2, or - i A1,A2.
Value range: A1…A14 and B1…B8
NOTE: Items from A1 to A14 indicate that OS parameters need to be checked but not to be set. Items from B1 to B8 indicate that system parameters need to be set to expected values. Items A and items B cannot be simultaneously set.
For details, see Table 1.
-
-f
Specifies the file of a host name list.
NOTE: The -f and -h parameters cannot be used together.
Value range: a host name list
-
-h
Specifies the name of a host to be checked. You can specify multiple hosts and separate the hosts with commas (,).
Value range: a host name of MogDB. If no host is specified, the current host is checked.
-
-X
Specifies the XML configuration file of MogDB.
-
-detail
Displays detailed check results.
-
-o
Specifies the file for saving OS check reports.
If this parameter is not specified, OS check results are displayed on the screen.
-
-l
Specifies a log file and its save path.
Default value: /tmp/gs_checkos/gs_checkos-YYYY-MM-DD_hhmmss.log
-
-?, -help
Displays help information.
-
-V, -version
Displays version information.
Number | Check Item | Description |
---|---|---|
A1 | OS version status | Check the OS version. Ensure that the host platform supports openEuler or CentOS. In addition, you need to ensure that the all host platforms of MogDB belong to the same hybrid range. |
A2 | Kernel version status | Check the kernel version. |
A3 | Unicode status | Check the character set. Ensure that the character sets of MogDB hosts are consistent. |
A4 | Time zone status | Checks the time zone setting. Ensure that the time zones of MogDB hosts are consistent. |
A5 | Swap memory status | Check the swap partition. Ensure that the swap partition size of each host is less than or equals to the total memory size of the host. |
A6 | System control parameters status | Check the kernel parameter. Ensure that the parameter value of the current kernel is consistent with the default value. For details, see OS Parameters. |
A7 | File system configuration status | Check the system file handle. Ensure that the parameter value of the system file handle is greater than or equal to 1000000. Check the thread stack size: Ensure that the thread size is greater than or equal to 3072 KB. Check the maximum available virtual memory of processes. Ensure that the maximum available virtual memory of system processes is unlimited. |
A8 | Disk configuration status | Check the hard disk mounting parameter. Ensure that the disk format is XFS and its mounting mode is "rw,noatime,inode64,allocsize=16m". |
A9 | Pre-read block size status | Check the pre-read parameter. Ensure that the expected value of the pre-read parameter is 16384. |
A10 | IO scheduler status | Check the I/O scheduling policy. Ensure that the I/O scheduling policy is deadline. |
A11 | Network card configuration status | Check the NIC smaller than 10GE. - Ensure that mtu of the NIC is 1500. Check the NIC larger than 10GE. - When the NIC is in unbinding mode and is a 10GE card, ensure that the value of mtu is 1500 and the value of rx/tx is greater than or equal to 4096. - When the NIC is in binding mode, ensure that the type of each binding NIC is 10GE, the value of mtu is 1500, and the value of rx/tx is greater than or equal to 4096. - The NIC of MogDB's peripheral devices (such as switches) should be set to the same as that of the MogDB hosts. |
A12 | Time consistency status | Check the time consistency status. Ensure that the NTP service is started and the system time deviation of each MogDB host does not exceed 60s. |
A13 | Firewall service status | Check the firewall status. Ensure that the firewall is disabled. |
A14 | THP service status | Check the THP service status. Ensure that the THP service is disabled. |
B1 | Set system control parameters | Sets the kernel parameter. When the actual value does not meet check requirements, reset the parameter whose result is Abnormal. Do not set the Warning parameter here. You can set the value of Warning as needed. |
B2 | Set file system configuration value | Set the parameter of system file handles. Set the number of system file handles if it is less than 1000000. Set the thread stack size. Set the thread stack size if it is less than 3072 KB. Set the maximum available virtual memory of processes: If the maximum available virtual memory of system processes is not unlimited, change it to unlimited. |
B3 | Set pre-read block size value | Set the hard disk pre-read parameter: When the actual value is less than 16384, reset the parameter. |
B4 | Set IO scheduler value | Set the I/O configuration item. If the actual value of the system is not deadline, reset the parameter. |
B5 | Set network card configuration value | Set the 10GE NIC parameters. Set the rx and tx parameters that do not meet 10GE NIC requirements. Do not set the mtu parameter. |
B6 | Set THP service | Set the THP service. If the THP service is enabled, disable it. |
B7 | Set RemoveIPC value | Check EulerOS attributes. Set the value of RemoveIPC in files /usr/lib/systemd/system/systemd-logind.service and /etc/systemd/logind.conf to no. |
B8 | Set Session Process | Set a remote device to inherit default system resources. Modify the /etc/pam.d/sshd service file and add the session required pam_limits.so configuration item to control resources used by users. |
NOTE:
- Item A6 needs to be checked based on the [/etc/sysctl.conf] and [SUGGEST:/etc/sysctl.conf] domains in the check_list.conf configuration file. If the parameter value in [/etc/sysctl.conf] differs from the actual value, an Abnormal message is displayed during the check of item A6. You can set the parameter in item B1. If the parameter value in [SUGGEST:/etc/sysctl.conf] differs from the actual value, a Warning message is displayed during the check of item A6. You can manually set the parameter in item B1 as needed.
- Item A7 checks items specified by the open file parameter in the [/etc/security/ limits.conf] domain in the check_list.conf configuration file. You can set the parameter in item B2.
- The mtu, rx, and tx parameters of item A11 need to be checked based on the [/sbin/ifconfig] domain in the check_list.conf configuration file. You can set the rx and tx parameters using item B5 and set the mtu parameter manually.
- Use configured gs_checkos kernel parameter value and file handles parameter value to restart the new session.
OS Parameters
Table 2 OS parameters
Parameter | Description | Recommended Value |
---|---|---|
net.ipv4.tcp_max_tw_buckets | Specifies the maximum number of TCP/IP connections concurrently remaining in the 、 TIME_WAIT state. If the number of TCP/IP connections concurrently remaining in the TIME_WAIT state exceeds the value of this parameter, the TCP/IP connections in the TIME_WAIT state will be released immediately, and alarm information will be printed. |
10000 |
net.ipv4.tcp_tw_reuse | Reuses sockets whose status is TIME-WAIT for new TCP connections. - 0: This function is disabled. - 1: This function is enabled. |
1 |
net.ipv4.tcp_tw_recycle | Rapidly reclaims sockets whose status is TIME-WAIT in TCP connections. - 0: This function is disabled. - 1: This function is enabled. |
1 |
net.ipv4.tcp_keepalive_time | Specifies how often Keepalived messages are sent through TCP connections when Keepalived is enabled. | 30 |
net.ipv4.tcp_keepalive_probes | Specifies the number of Keepalived detection packets sent through a TCP connection before the connection is regarded invalid. The product of the parameter value multiplied by the value of the tcp_keepalive_intvl parameter determines the response timeout duration after a Keepalived message is sent through a connection. | 9 |
net.ipv4.tcp_keepalive_intvl | Specifies how often a detection packet is re-sent when the previous packets are not acknowledged. | 30 |
net.ipv4.tcp_retries1 | Specifies the maximum TCP reattempts during the connection establishment process. | 5 |
net.ipv4.tcp_syn_retries | Specifies the maximum SYN packet reattempts in the TCP. | 5 |
net.ipv4.tcp_synack_retries | Specifies the maximum SYN response packet reattempts in the TCP. | 5 |
net.ipv4.tcp_retries2 | Specifies the number of times that the kernel re-sends data to a connected remote host. A smaller value leads to earlier detection of an invalid connection to the remote host, and the server can quickly release this connection. If "connection reset by peer" is displayed, increase the value of this parameter to avoid the problem. |
12 |
vm.overcommit_memory | Specifies the kernel check method during memory allocation. - 0: The system accurately calculates the current available memory. - 1: The system returns a success message without a kernel check. - 2: The system returns a failure message if the memory size you have applied for exceeds the result of the following formula: Total memory size x Value of vm.overcommit_ratio /100 + Total SWAP size.The default value for is 2, which is too conservative. The recommended value is 0. If memory usage is high, set this parameter to 1. |
0 |
net.ipv4.tcp_rmem | Specifies the free memory in the TCP receiver buffer. Three memory size ranges in the unit of page are provided: min, default, and max. | 8192 250000 16777216 |
net.ipv4.tcp_wmem | Specifies the free memory in the TCP sender buffer. Three memory size ranges in the unit of page are provided: min, default, and max. | 8192 250000 16777216 |
net.core.wmem_max | Specifies the maximum size of the socket sender buffer. | 21299200 |
net.core.rmem_max | Specifies the maximum size of the socket receiver buffer. | 21299200 |
net.core.wmem_default | Specifies the default size of the socket sender buffer. | 21299200 |
net.core.rmem_default | Specifies the default size of the socket receiver buffer. | 21299200 |
net.ipv4.ip_local_port_range | Specifies the range of temporary ports that can be used by a physical server. | 26000-65535 |
kernel.sem | Specifies the kernel semaphore. | 250 6400000 1000 25600 |
vm.min_free_kbytes | Specifies the minimum free physical memory reserved for unexpected page breaks. | 5% of the total system memory |
net.core.somaxconn | Specifies the maximum length of the listening queue of each port. This is a global parameter. | 65535 |
net.ipv4.tcp_syncookies | Specifies whether to enable SYN cookies to guard the OS against SYN attacks when the SYN waiting queue overflows. - 0: The SYN cookies are disabled. - 1: The SYN cookies are enabled. |
1 |
net.core.netdev_max_backlog | Specifies the maximum number of data packets that can be sent to the queue when the rate at which the network device receives data packets is higher than that at which the kernel processes the data packets. | 65535 |
net.ipv4.tcp_max_syn_backlog | Specifies the maximum number of unacknowledged connection requests to be recorded. | 65535 |
net.ipv4.tcp_fin_timeout | Specifies the default timeout duration. | 60 |
kernel.shmall | Specifies the total shared free memory of the kernel. | 1073741824 |
kernel.shmmax | Specifies the maximum value of a shared memory segment. | 4398046511104 |
net.ipv4.tcp_sack | Specifies whether selective acknowledgment is enabled. The selective acknowledgment on out-of-order packets can increase system performance. Restricting users to sending only lost packets (for wide area networks) should be enabled, but this will increase CPU usage. - 0: This function is disabled. - 1: This function is enabled. |
1 |
net.ipv4.tcp_timestamps | Specifies whether the TCP timestamp (12 bytes are added in the TCP packet header) enables a more accurate RTT calculation than the retransmission timeout (for details, see RFC 1323) for better performance. - 0: This function is disabled. - 1: This function is enabled. |
1 |
vm.extfrag_threshold | When system memory is insufficient, Linux will score the current system memory fragments. If the score is higher than the value of vm.extfrag_threshold , kswapd triggers memory compaction. When the value of this parameter is close to 1000, the system tends to swap out old pages when processing memory fragments to meet the application requirements. When the value of this parameter is close to 0, the system tends to do memory compaction when processing memory fragments. |
500 |
vm.overcommit_ratio | When the system uses the algorithms where memory usage never exceeds the thresholds, the total memory address space of the system cannot exceed the value of swap+RAM multiplied by the percentage specified by this parameter. When the value of vm.overcommit_memory ~ is set to 2, this parameter takes effect. |
90 |
MTU | Specifies the maximum transmission unit (MTU) for a node NIC. The default value is 1500 in the OS. You can set it to 8192 to improve the performance of sending and receiving data using SCTP. | 8192 |
File System Parameters
-
soft nofile
Indicates the soft restriction. The number of file handles used by a user can exceed this setting value, but an alarm message will be sent if the value is exceeded.
Recommended value: 1000000
-
hard nofile
Indicates the hard restriction. The number of file handles used by a user cannot exceed this setting value.
Recommended value: 1000000
-
stack size
Indicates the thread stack size.
Recommended value: 3072
Examples
Run the following commands to check the OS parameters:
gs_checkos -i A -h plat1 -X /opt/software/mogdb/clusterconfig.xml --detail -o /var/log/checkos
Performing operation system check/set. Output the result to the file /var/log/checkos.
Operation system check/set is completed.
Total numbers:14. Abnormal numbers:0. Warning number:1.
Query check results.
vim /var/log/checkos
Checking items:
A1. [ OS version status ] : Normal
A2. [ MogDB version status ] : Normal
A3. [ Unicode status ] : Normal
A4. [ Time zone status ] : Normal
A5. [ Swap memory status ] : Normal
A6. [ System control parameters status ] : Normal
A7. [ File system configuration status ] : Normal
A8. [ Disk configuration status ] : Normal
A9. [ Pre-read block size status ] : Normal
A10.[ IO scheduler status ] : Normal
A11.[ Network card configuration status ] : Normal
A12.[ Time consistency status ] : Warning
A13.[ Firewall service status ] : Normal
A14.[ THP service status ] : Normal