postgresql/src/backend/bootstrap
Peter Eisentraut 4f622503d6 Make attstattarget nullable
This changes the pg_attribute field attstattarget into a nullable
field in the variable-length part of the row.  If no value is set by
the user for attstattarget, it is now null instead of previously -1.
This saves space in pg_attribute and tuple descriptors for most
practical scenarios.  (ATTRIBUTE_FIXED_PART_SIZE is reduced from 108
to 104.)  Also, null is the semantically more correct value.

The ANALYZE code internally continues to represent the default
statistics target by -1, so that that code can avoid having to deal
with null values.  But that is now contained to the ANALYZE code.
Only the DDL code deals with attstattarget possibly null.

For system columns, the field is now always null.  The ANALYZE code
skips system columns anyway.

To set a column's statistics target to the default value, the new
command form ALTER TABLE ... SET STATISTICS DEFAULT can be used.  (SET
STATISTICS -1 still works.)

Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://www.postgresql.org/message-id/flat/4da8d211-d54d-44b9-9847-f2a9f1184c76@eisentraut.org
2024-01-13 18:14:53 +01:00
..
.gitignore Build all Flex files standalone 2022-09-04 12:09:01 +07:00
Makefile Remove distprep 2023-11-06 15:18:04 +01:00
bootparse.y Update copyright for 2024 2024-01-03 20:49:05 -05:00
bootscanner.l Update copyright for 2024 2024-01-03 20:49:05 -05:00
bootstrap.c Make attstattarget nullable 2024-01-13 18:14:53 +01:00
meson.build Update copyright for 2024 2024-01-03 20:49:05 -05:00