Catalog Reference

The SQreamDB database uses a schema called sqream_catalog that contains information about database objects such as tables, columns, views, and permissions. Some additional catalog tables are used primarily for internal analysis and may differ across SQreamDB versions.

What Information Does the Schema Contain?

The schema contains data management tables with information about structure and management of database elements, including tables, schemas, queries, and permissions, and physical storage and organization of data tables of extents, chunk columns, chunks, and delete predicates.

How to Get Table Information?

To get the information stored on a table, use this syntax, as in this example of working with the parameters table:

SELECT * FROM sqream_catalog.parameters;

To get the table ddl, use this syntax, as in this example of working with the parameters table:

SELECT get_ddl('sqream_catalog.parameters');

Database Management Tables

Database Object

Table

Clustering Keys

clustering_keys

Columns

columns, external_table_columns

Databases

databases

Parameters

parameters

Permissions

table_permissions, database_permissions, schema_permissions, permission_types, udf_permissions, sqream_catalog.table_default_permissions

Queries

savedqueries

Roles

roles, role_memberships

Schemas

schemas

Tables

tables, external_tables

Views

views

User Defined Functions

user_defined_functions

Data Storage and Organization Tables

Database Object

Table

Extents

Shows extents

Chunk columns

Shows chunks_columns

Chunks

Shows chunks

Delete predicates

Shows delete_predicates. For more information, see Deleting Data