Schemas

The following table describes the schemas supported in GaussDB.

**Table 1** Schemas supported in GaussDB
Schema	Description
blockchain	Stores the user history table that is automatically created when a tamper-proof table is created in the ledger database. (The current feature is a lab feature. Contact Huawei technical support before using it.)
cstore	Stores auxiliary tables related to column-store tables, such as CUDesc and Delta tables.
dbe_perf	Diagnoses performance issues and is also the data source of WDR snapshots. After a database is installed, only the initial user and monitoring administrator have permission to view views and functions in the DBE_PERF scheme by default.
snapshot	Manages data related to WDR snapshots. By default, the initial user or monitoring administrator can access the data.
sqladvsior	Recommends distribution columns. For details, see Distribution Column Recommendation Functions.
sys	Provides the system information view APIs.
pg_catalog	Maintains system catalog information, including system catalogs and all built-in data types, functions, and operators.
pg_toast	Stores large objects (for internal use).
public	Public schema. By default, created tables (and other objects) are automatically put into this schema.
pkg_service	Manages information about the package service.
pkg_util	Manages information about the package tool.
dbe_raw	Advanced function package dbe_raw, which is used to convert raw data, obtain substrings, and calculate the length.
dbe_session	Advanced function package dbe_session, which is used to set the value of a specified attribute and support user query and verification.
dbe_lob	Advanced function package dbe_lob, which is used to read, write, and copy large files (CLOB/BLOB).
dbe_match	Advanced function package dbe_match, which is used to compare character string similarity.
dbe_task	Advanced function package dbe_task, which is used to schedule job tasks, including submitting tasks, canceling tasks, synchronizing task status, and updating task information, so that the database can periodically execute specific tasks.
dbe_sql	Advanced function package dbe_sql, which is used to execute dynamic SQL statements and construct query and other commands during application running.
dbe_file	Advanced function package dbe_file, which is used to read, copy, write, delete, and rename external database files.
dbe_output	Advanced function package dbe_output, which is used to print output information.
dbe_random	Advanced function package dbe_random, which is used to generate random seeds and random numbers.
dbe_application_info	Advanced function package dbe_application_info, which is used for recording client information.
dbe_utility	Advanced function package dbe_utility, which is used to invoke the debugging tool in a stored procedure, for example, to print error stacks.
dbe_scheduler	Advanced function package dbe_scheduler, which is used to create scheduled tasks and enable the database to periodically execute specified tasks through programs and schedules. You can also perform external database tasks by authorizing and providing certificates.
information_schema	Stores information about objects defined in the current database.

**Table 2** Schemas disabled in GaussDB
Schema	Description
dbe_pldebugger	This view is used to debug plpgsql functions and stored procedures. Currently, this view is not supported. An error message "unsupported" is displayed when the interface is invoked in this view.
db4ai	Manages data of different versions in AI training.
dbe_pldeveloper	Compiles and debugs user stored procedures.
dbe_sql_util	Manages statement patches.

The following APIs are not supported in distributed deployment mode:

bool dbe_sql_util.create_hint_sql_patch(name, bigint, text, text DEFAULT NULL::text, boolean DEFAULT true)
bool dbe_sql_util.create_abort_sql_patch(name, bigint, text DEFAULT NULL::text, boolean DEFAULT true)
bool dbe_sql_util.drop_sql_patch(name)
bool dbe_sql_util.enable_sql_patch(name)
bool dbe_sql_util.disable_sql_patch(name)
record dbe_sql_util.show_sql_patch(patch_name name, OUT unique_sql_id bigint, OUT enable boolean, OUT abort boolean, OUT hint_str text)