What is returned with: SELECT 3 ORDER BY 1 LIMIT 2 OFFSET 1;
No rows
One row with 3
Two rows with 1,2
Exception is raised
What is the default value of default_statistics_target (>= 8.4):
10
100
1000
1000000
What is returned with: SELECT pg_typeof(relname) from pg_class limit 1;
Text
Varchar
Oid
Name
What is the max size of single file for table chunk:
10MB
1GB
4GB
256GB
What is the default ON COMMIT for temporary tables:
PRESERVE ROWS
DELETE ROWS
DROP
There is no default, you must always specify it
How to cancel trigger operation on current row:
Return empty
Return null
Return void
Break
Which is not query planner setting:
Constraint_exclusion
Cpu_tuple_cost
Enable_sort
Distinct_limit
Which does not end current transaction:
COMMIT;
ROLLBACK;
ABORT;
CANCEL;
Which lock is not conflicting with SHARE ROW EXCLUSIVE:
SHARE UPDATE EXCLUSIVE
ROW SHARE
SHARE ROW EXCLUSIVE
ROW EXCLUSIVE
Which lock is acquired by the DROP TABLE, TRUNCATE, REINDEX, CLUSTER, VACUUM FULL, and REFRESH MATERIALIZED VIEW:
SHARE UPDATE EXCLUSIVE
EXCLUSIVE
ACCESS EXCLUSIVE
ROW EXCLUSIVE
Where you can check about bgwriter statistics:
Pg_stat_database
Pg_stat_bgwriter
Pg_stat_archiver
Pg_stat_replication
Which is not a phase of VACUUM?
Initializing
Scanning heap
Running analyze
Truncating heap
CREATE SERVER:
Creates foreign server
Creates local database
Creates local cluster
Creates foreign cluster
Which is not an auth method in pg_hba.conf file?
Scram-sha-256
Shadow
Md5
Ldap
Which version of PostgreSQL introduces CREATE MATERIALIZED VIEW:
8.2
8.6
9.0
9.3
Which version of PostgreSQL introduces CREATE RECURSIVE VIEW:
8.0
8.4
9.0
9.3
Which you cannot DISCARD?
PLANS
SETTINGS
SEQUENCES
TEMPORARY
Where is stored info about free space inside table structure?
Free Space Map
Visibility Map
In the header of index file
In pg_class
What does CLOSE do?
Closes connection
Closes cursor
This is spatial operator
There is no such command in PostgreSQL
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