postgresql alter table change column type

When set to a positive value, ANALYZE will assume that the column contains exactly the specified number of distinct nonnull values. n_distinct affects the statistics for the table itself, while n_distinct_inherited affects the statistics gathered for the table plus its inheritance children. Currently, the only defined per-attribute options are n_distinct and n_distinct_inherited, which override the number-of-distinct-values estimates made by subsequent ANALYZE operations. This form sets or resets per-attribute options. SET STATISTICS acquires a SHARE UPDATE EXCLUSIVE lock. For more information on the use of statistics by the PostgreSQL query planner, refer to Section 14.2. The target can be set in the range 0 to 10000 alternatively, set it to -1 to revert to using the system default statistics target ( default_statistics_target). This form sets the per-column statistics-gathering target for subsequent ANALYZE operations.

sequence_option is an option supported by ALTER SEQUENCE such as INCREMENT BY. These forms alter the sequence that underlies an existing identity column. See also this related question it's about Rails migrations, but the underlying cause is the same and the answer applies. If DROP IDENTITY IF EXISTS is specified and the column is not an identity column, no error is thrown. ALTER TABLE test ALTER COLUMN x TYPE integer USING (trim(x)::integer) ALTER TABLE Thanks muistooshort for adding the USING link. Like SET DEFAULT, these forms only affect the behavior of subsequent INSERT and UPDATE commands they do not cause rows already in the table to change. These forms change whether a column is an identity column or change the generation attribute of an existing identity column. RENAME CONSTRAINT constraint_name TO new_constraint_nameĪLTER TABLE ALL IN TABLESPACE name ]ĪTTACH PARTITION partition_name AS IDENTITY

Postgresql alter table change column type