Other Functions
plan_seed()
Description: Obtains the seed value of the previous query statement (internal use).
Return type: int
pg_stat_get_env()
Description: Obtains the environment variable information of the current node. Only users with the sysadmin or monitor admin permission can access the environment variable information.
Return type: record
Example:
openGauss=# select pg_stat_get_env(); pg_stat_get_env --------------------------------------------------------------------------------------------------------------------------------------- (coordinator1,localhost,144773,49100,/data1/GaussDB_Kernel_TRUNK/install,/data1/GaussDB_Kernel_TRUNK/install/data/coordinator1,pg_log) (1 row)pg_catalog.plancache_clean()
Description: Clears the global plan cache that is not used on nodes.
Return type: Boolean
pg_catalog.plancache_status()
Description: Displays information about the global plan cache on nodes. The information returned by the function is the same as that in GLOBAL_PLANCACHE_STATUS.
Return type: record
textlen(text)
Description: Provides the method of querying the logical length of text.
Return type: int
threadpool_status()
Description: Displays the status of worker threads and sessions in the thread pool.
Return type: record
get_local_active_session()
Description: Provides sampling records of the historical active sessions stored in the memory of the current node.
Return type: record
pg_stat_get_thread()
Description: Provides status information about all threads on the current node. Users with the sysadmin or monitor admin permission can view information about all threads, and common users can view only their own thread information.
Return type: record
pg_stat_get_sql_count()
Description: Provides the counts of the SELECT, UPDATE, INSERT, DELETE, and MERGE INTO statements executed on the current node. Users with the sysadmin or monitor admin permission can view information about all users, and common users can view only their own statistics.
Return type: record
pg_stat_get_data_senders()
Description: Provides detailed information about the data-copy sending thread active at the moment.
Return type: record
get_wait_event_info()
Description: Provides detailed information about the wait event.
Return type: record
generate_wdr_report(begin_snap_id bigint, end_snap_id bigint, report_type cstring, report_scope cstring, node_name cstring)
Description: Generates system diagnosis reports based on two snapshots. You need to run the command in the postgres database. By default, the initial user or the user with the monadmin permission can access the database. In V500R001C20SPC002 and earlier versions, the initial user or the user with the sysadmin permission can access the database. The result can be queried only in the system database but cannot be queried in the user database.
Return type: record
Table 1 generate_wdr_report parameter description
create_wdr_snapshot()
Description: Manually generates system diagnosis snapshots. This function requires the sysadmin permission.
Return type: text
kill_snapshot()
Description: Kills the WDR snapshot backend thread. Users who invoke this function must have the SYSADMIN permission, the REPLICATION permission, or inherit the gs_role_replication permission of the built-in role.
Return type: void
capture_view_to_json(text,integer)
Description: Saves the view result to the directory specified by GUC: perf_directory. If is_crossdb is set to 1, the view is accessed once for all databases. If the value of is_crossdb is 0, the current database is accessed only once. Only users with the sysadmin or monitor admin permission can execute this function.
Return type: int
reset_unique_sql
Description: Clears the unique SQL statements in the memory of the database node. (The sysadmin permission is required.)
Return type: Boolean
Table 2 reset_unique_sql parameter description
Clearance scope type. The options are as follows:
NOTICE:- The values GLOBAL and LOCAL of scope apply to distributed databases. For openGauss, the values have the same meaning, indicating that the local node is cleared.
- The value BY_CNID of clean_type applies only to distributed databases and is invalid for openGauss.
wdr_xdb_query(db_name_str text, query text)
Description: Provides the capability of executing local cross-database queries. For example, when connecting to the Postgres database, access tables in the test database.
select col1 from wdr_xdb_query('dbname=test','select col1 from t1') as dd(col1 int);Return type: record
pg_wlm_jump_queue(pid int)
Description: Moves a task to the top of the queue of the primary node of the database.
Return type: Boolean
- true: success
- false: failure
gs_wlm_switch_cgroup(pid int, cgroup text)
Description: Moves a job to another Cgroup to change the job priority.
Return type: Boolean
- true: success
- false: failure
pv_session_memctx_detail(threadid tid, MemoryContextName text)
Description: Records information about the memory context MemoryContextName of the thread tid into the threadid**_timestamp.log** file in the $GAUSSLOG**/pg_log/${node*name}/dumpmem** directory. _threadid* can be obtained from sessid in the GS_SESSION_MEMORY_DETAIL view. In the officially released version, only the MemoryContextName that is an empty string (two single quotation marks indicate that the input is an empty string) is accepted. In this case, all memory context information is recorded. Otherwise, no operation is performed. For the DEBUG version for internal development and test personnel to debug, you can specify the MemoryContextName to be counted. In this case, all the memory usage of the context is recorded in the specified file. Only the administrator can execute this function.
Return type: Boolean
- true: success
- false: failure
pg_shared_memctx_detail(MemoryContextName text)
Description: Records information about the memory context MemoryContextName into the threadid**_timestamp.log** file in the $GAUSSLOG**/pg_log/${node*name}_/dumpmem* directory. This function is provided only for internal development and test personnel to debug in the DEBUG version. Calling this function in the officially released version does not involve any operation. Only the administrator can execute this function.
Return type: Boolean
- true: success
- false: failure
local_bgwriter_stat()
Description: Displays the information about pages flushed by the bgwriter thread of this instance, number of pages in the candidate buffer chain, and buffer elimination information.
Return type: record
local_candidate_stat()
Description: Displays the number of pages in the candidate buffer chain of this instance and buffer elimination information, including the normal buffer pool and segment buffer pool.
Return type: record
local_ckpt_stat()
Description: Displays the information about checkpoints and flushing pages of the current instance.
Return type: record
local_double_write_stat()
Description: Displays the doublewrite file status of the current instance.
Return type: record
Table 3 local_double_write_stat parameters
local_single_flush_dw_stat()
Description: Displays the elimination of dual-write files on a single page in the instance.
Return type: record
local_pagewriter_stat()
Description: Displays the page flushing information and checkpoint information of the current instance.
Return type: record
local_redo_stat()
Description: Displays the replay status of the current standby instance.
Return type: record
Note: The returned replay status includes the current replay position and the replay position of the minimum restoration point.
local_recovery_status()
Description: Displays log flow control information about the primary and standby nodes.
Return type: record
gs_wlm_node_recover(boolean isForce)
Description: Obtains top SQL query statement-level statistics recorded in the current memory. If the input parameter is not 0, the information is cleared from the memory.
Return type: record
gs_wlm_node_clean(cstring nodename)
Description: Clears data after the dynamic load management node is faulty. Only administrators can execute this function. This function is called by the database instance management module. You are not advised to directly call this function. This view is not supported in a centralized or standalone system.
Return type: Boolean
gs_cgroup_map_ng_conf(group name)
Description: Reads the Cgroup configuration file of a specified logical database.
Return type: record
gs_wlm_switch_cgroup(sess_id int8, cgroup name)
Description: Switches the Cgroup of a specified session.
Return type: record
comm_client_info()
Description: Queries information about active client connections of a single node.
Return type: SETOF record
pg_sync_cstore_delta(text)
Description: Synchronizes the delta table structure of a specified column-store table with that of the column-store primary table.
Return type: bigint
pg_sync_cstore_delta()
Description: Synchronizes the delta table structure of all column-store tables with that of the column-store primary table.
Return type: bigint
pg_get_flush_lsn()
Description: Returns the position of the Xlog flushed from the current node.
Return type: text
pg_get_sync_flush_lsn()
Description: Returns the position of the Xlog flushed by the majority on the current node.
Return type: text
gs_create_log_tables()
Description: Creates foreign tables and views for run logs and performance logs.
Return type: void
Example:
openGauss=# select gs_create_log_tables(); gs_create_log_tables ---------------------- (1 row)dbe_perf.get_global_full_sql_by_timestamp(start_timestamp timestamp with time zone, end_timestamp timestamp with time zone)
Description: Obtains full SQL information at the database level. The result can be queried only in the system database but cannot be queried in the user database.
Return type: record
Table 4 dbe_perf.get_global_full_sql_by_timestamp parameter description
dbe_perf.get_global_slow_sql_by_timestamp(start_timestamp timestamp with time zone, end_timestamp timestamp with time zone)
Description: Obtains slow SQL information at the database level. The result can be queried only in the system database but cannot be queried in the user database.
Return type: record
Table 5 dbe_perf.get_global_slow_sql_by_timestamp parameter description
statement_detail_decode(detail text, format text, pretty boolean)
Description: Parses the details column in a full or slow SQL statement. The result can be queried only in the system database but cannot be queried in the user database.
Return type: text
Table 6 statement_detail_decode parameter description
get_prepared_pending_xid
Description: Returns nextxid when restoration is complete.
Parameter: nan
Return type: text
pg_clean_region_info
Description: Clears the regionmap.
Parameter: nan
Return type: character varying
pg_get_delta_info
Description: Obtains delta information from a single DN.
Parameter: rel text, schema_name text
Return type: part_name text, live_tuple bigint, data_size bigint, and blocknum bigint
pg_get_replication_slot_name
Description: Obtains the slot name.
Parameter: nan
Return type: text
pg_get_running_xacts
Description: Obtains running xact.
Parameter: nan
Return type: handle integer, gxid xid, state tinyint, node text, xmin xid, vacuum boolean, timeline bigint, prepare_xid xid, pid bigint, and next_xid xid
pg_get_variable_info
Description: Obtains the shared memory variable cache.
Parameter: nan
Return type: node_name text, nextOid oid, nextXid xid, oldestXid xid, xidVacLimit xid, oldestXidDB oid, lastExtendCSNLogpage xid, startExtendCSNLogpage xid, nextCommitSeqNo xid, latestCompletedXid xid, and startupMaxXid xid
pg_get_xidlimit
Description: Obtains transaction ID information from the shared memory.
Parameter: nan
Return type: nextXid xid, oldestXid xid, xidVacLimit xid, xidWarnLimit xid, xidStopLimit xid, xidWrapLimit xid, and oldestXidDB oid
get_global_user_transaction()
Description: Returns transaction information about each user on all nodes.
Return type: node_name name, usename name, commit_counter bigint, rollback_counter bigint, resp_min bigint, resp_max bigint, resp_avg bigint, resp_total bigint, bg_commit_counter bigint, bg_rollback_counter bigint, bg_resp_min bigint, bg_resp_max bigint, bg_resp_avg bigint, and bg_resp_total bigint
pg_collation_for
Description: Returns the sorting rule corresponding to the input parameter string.
Parameter: any (Explicit type conversion is required for constants.)
Return type: text
pgxc_unlock_for_sp_database(name Name)
Description: Releases a specified database lock.
Parameter: database name
Return type: Boolean
pgxc_lock_for_sp_database(name Name)
Description: Locks a specified database.
Parameter: database name
Return type: Boolean
copy_error_log_create()
Description: Creates the error table (public.pgxc_copy_error_log) required for creating the COPY FROM error tolerance mechanism.
Return type: Boolean
NOTE:- This function attempts to create the public.pgxc_copy_error_log table. For details about the table, see Table 7.
- Create the B-tree index on the relname column and execute REVOKE ALL on public.pgxc_copy_error_log FROM public to manage permissions for the error table (the permissions are the same as those of the COPY statement).
- public.pgxc_copy_error_log is a row-store table. Therefore, this function can be executed and COPY error tolerance is available only when row-store tables can be created in the database instance. Note that after the GUC parameter enable_hadoop_env is enabled, row-store tables cannot be created in the database instance (the default value is off for GaussDB Kernel).
- Same as the error table and the COPY statement, the function requires sysadmin or higher permissions.
- If the public.pgxc_copy_error_log table or the copy_error_log_relname_idx index exists before the function creates it, the function will report an error and roll back.
Table 7 Error table public.pgxc_copy_error_log
Name of the source data file where a data format error occurs
Number of the row where a data format error occurs in a source data file
dynamic_func_control(scope text, function_name text, action text, “{params}” text[])
Description: Dynamically enables built-in functions. Currently, only full SQL statements can be dynamically enabled.
Return type: record
Table 8 Parameter description of dynamic_func_control
gs_parse_page_bypath(path text, blocknum bigint, relation_type text, read_memory boolean)
Description: Parses a specified table page and returns the path for storing the parsed content.
Return type: text
Note: Only the system administrator or O&M administrator can execute this function.
Table 9 gs_parse_page_bypath parameters
gs_xlogdump_lsn(start_lsn text, end_lsn text)
Description: Parses Xlogs within the specified LSN range and returns the path for storing the parsed content. You can use pg_current_xlog_location() to obtain the current Xlog position.
Return type: text
Parameters: LSN start position and LSN end position
Note: Only the system administrator or O&M administrator can execute this function.
gs_xlogdump_xid(c_xid xid)
Description: Parses Xlogs of a specified XID and returns the path for storing the parsed content. You can use txid_current() to obtain the current XID.
Parameter: XID
Return type: text
Note: Only the system administrator or O&M administrator can execute this function.
gs_xlogdump_tablepath(path text, blocknum bigint, relation_type text)
Description: Parses logs corresponding to a specified table page and returns the path for storing the parsed content.
Return type: text
Note: Only the system administrator or O&M administrator can execute this function.
Table 10 gs_xlogdump_tablepath parameters
gs_xlogdump_parsepage_tablepath(path text, blocknum bigint, relation_type text, read_memory boolean)
Description: Parses the specified table page and logs corresponding to the table page and returns the path for storing the parsed content. It can be regarded as one execution of gs_parse_page_bypath and gs_xlogdump_tablepath. The prerequisite for executing this function is that the table file exists. To view logs of deleted tables, call gs_xlogdump_tablepath.
Return type: text
Note: Only the system administrator or O&M administrator can execute this function.
Table 11 gs_xlogdump_parsepage_tablepath parameters
gs_index_verify(Oid oid, uint32:wq blkno)
Description: Checks whether the sequence of keys on the UBtree index page or index tree is correct.
Return type: record
Table 12 gs_index_verify parameters
gs_index_recycle_queue(Oid oid, int type, uint32 blkno)
Description: Parses the UBtree index recycling queue information.
Return type: record
Table 13 gs_index_recycle_queue parameters
gs_stat_wal_entrytable(int64 idx)
Description: Exports the content of the write-ahead log insertion status table in the Xlog.
Return type: record
Table 14 gs_stat_wal_entrytable parameters
Determines whether the Xlog corresponding to the current entry has been completely copied to the WAL buffer:
gs_walwriter_flush_position()
Description: Outputs the refresh position of write-ahead logs.
Return type: record
Table 15 gs_walwriter_flush_position parameters
gs_walwriter_flush_stat(int operation)
Description: Collects statistics on the frequency of writing and synchronizing write-ahead logs, data volume, and Xlog file information.
Return type: record
Table 16 gs_walwriter_flush_stat parameters
gs_comm_proxy_thread_status()
Description: Collects statistics on data packets sent and received by the proxy communication library comm_proxy when a user-mode network is configured for the database instance.
Parameter: nan
Return type: record
NOTE:
The query result of this function is displayed only when the user-mode network is deployed in a centralized environment and enable_dfx in comm_proxy_attr is set to true. In other scenarios, an error message is displayed, indicating that queries are not supported.