System Views
This section is a reference for a set of system views that capture information about resource
utilization, inflight queries, active loads, and other operational statistics. You can query
these views via ybsql
or other SQL query tools.
information_schema
tables and views are provided only for
compatibility with Postgres-compliant tools. For database administration, Yellowbrick
recommends using the views in the sys
schema, as documented in this
section. These views provide significant Yellowbrick-specific information that is not
available under information_schema
. sys
schema. For example, run this command:
premdb=# set schema 'sys';
SET
premdb=# \dvS
List of relations
Schema | Name | Type | Owner
--------+----------------------+------+---------
sys | backup | view | brumsby
sys | blade | view | brumsby
sys | column | view | brumsby
sys | database | view | brumsby
...
premdb=# select * from sys.log_query;
...
Note that all users can see the list of system views, but regular users may not have access to
the data they return. To grant access to the data in system views, use the GRANT command. For example, you
can grant SELECT
on all sys
schema views or a specific view.
Users who have SELECT
privilege on any column of a table will be able to see
that table in any view that represents the table's metadata (such as
sys.column
, sys.table
, or
sys.table_info
). Users who are not superusers must be logged into the
database where a table resides to see any data about that table in a system view.
sys
schema.premdb=# create table table2(c1 int, c2 int) distribute on(c1) sort on(c2);
ERROR: permission denied to create "sys.table2"
DETAIL: System catalog modifications are currently disallowed.
You cannot combine user-defined tables and system tables or views in the same query. One exception to this rule is the sys.const table, which can be queried in conjunction with regular tables.
The log retention time period, which determines the history that is retained in the
sys.log_*
views, is adjustable in the SMC. Go to .