postgres

History

Álvaro Herrera a379061a22 Allow NOT NULL constraints to be added as NOT VALID This allows them to be added without scanning the table, and validating them afterwards without holding access exclusive lock on the table after any violating rows have been deleted or fixed. Doing ALTER TABLE ... SET NOT NULL for a column that has an invalid not-null constraint validates that constraint. ALTER TABLE .. VALIDATE CONSTRAINT is also supported. There are various checks on whether an invalid constraint is allowed in a child table when the parent table has a valid constraint; this should match what we do for enforced/not enforced constraints. pg_attribute.attnotnull is now only an indicator for whether a not-null constraint exists for the column; whether it's valid or invalid must be queried in pg_constraint. Applications can continue to query pg_attribute.attnotnull as before, but now it's possible that NULL rows are present in the column even when that's set to true. For backend internal purposes, we cache the nullability status in CompactAttribute->attnullability that each tuple descriptor carries (replacing CompactAttribute.attnotnull, which was a mirror of Form_pg_attribute.attnotnull). During the initial tuple descriptor creation, based on the pg_attribute scan, we set this to UNRESTRICTED if pg_attribute.attnotnull is false, or to UNKNOWN if it's true; then we update the latter to VALID or INVALID depending on the pg_constraint scan. This flag is also copied when tupledescs are copied. Comparing tuple descs for equality must also compare the CompactAttribute.attnullability flag and return false in case of a mismatch. pg_dump deals with these constraints by storing the OIDs of invalid not-null constraints in a separate array, and running a query to obtain their properties. The regular table creation SQL omits them entirely. They are then dealt with in the same way as "separate" CHECK constraints, and dumped after the data has been loaded. Because no additional pg_dump infrastructure was required, we don't bump its version number. I decided not to bump catversion either, because the old catalog state works perfectly in the new world. (Trying to run with new catalog state and the old server version would likely run into issues, however.) System catalogs do not support invalid not-null constraints (because commit `14e87ffa5c` didn't allow them to have pg_constraint rows anyway.) Author: Rushabh Lathia <rushabh.lathia@gmail.com> Author: Jian He <jian.universality@gmail.com> Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org> Tested-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> Discussion: https://postgr.es/m/CAGPqQf0KitkNack4F5CFkFi-9Dqvp29Ro=EpcWt=4_hs-Rt+bQ@mail.gmail.com		8 months ago
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backend	Allow NOT NULL constraints to be added as NOT VALID	8 months ago
bin	Allow NOT NULL constraints to be added as NOT VALID	8 months ago
common	Use XLOG_CONTROL_FILE macro consistently for control file name.	8 months ago
fe_utils	add new list type simple_oid_string_list to fe-utils/simple_list	9 months ago
include	Allow NOT NULL constraints to be added as NOT VALID	8 months ago
interfaces	libpq: Fix some issues in TAP tests for service files	8 months ago
makefiles	aio: Add liburing dependency	9 months ago
pl	plpython: Add test for returning Python set from SETOF function	9 months ago
port	Compute CRC32C using AVX-512 instructions where available	9 months ago
template	thread-safety: gmtime_r(), localtime_r()	1 year ago
test	Allow NOT NULL constraints to be added as NOT VALID	8 months ago
timezone	pg_noreturn to replace pg_attribute_noreturn()	9 months ago
tools	Fix memory leaks in px_crypt_shacrypt().	9 months ago
tutorial	Doc: simplify the tutorial's window-function examples.	11 months ago
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Makefile.global.in	Update Unicode data to Unicode 16.0.0	9 months ago
Makefile.shlib	Remove AIX support	2 years ago
meson.build	Update copyright for 2025	12 months ago
nls-global.mk	…