postgresql/contrib/hstore
Heikki Linnakangas 5028f22f6e Switch to CRC-32C in WAL and other places.
The old algorithm was found to not be the usual CRC-32 algorithm, used by
Ethernet et al. We were using a non-reflected lookup table with code meant
for a reflected lookup table. That's a strange combination that AFAICS does
not correspond to any bit-wise CRC calculation, which makes it difficult to
reason about its properties. Although it has worked well in practice, seems
safer to use a well-known algorithm.

Since we're changing the algorithm anyway, we might as well choose a
different polynomial. The Castagnoli polynomial has better error-correcting
properties than the traditional CRC-32 polynomial, even if we had
implemented it correctly. Another reason for picking that is that some new
CPUs have hardware support for calculating CRC-32C, but not CRC-32, let
alone our strange variant of it. This patch doesn't add any support for such
hardware, but a future patch could now do that.

The old algorithm is kept around for tsquery and pg_trgm, which use the
values in indexes that need to remain compatible so that pg_upgrade works.
While we're at it, share the old lookup table for CRC-32 calculation
between hstore, ltree and core. They all use the same table, so might as
well.
2014-11-04 11:39:48 +02:00
..
data
expected
sql
.gitignore
hstore_compat.c Create function prototype as part of PG_FUNCTION_INFO_V1 macro 2014-04-18 00:03:19 -04:00
hstore_gin.c pgindent run for 9.4 2014-05-06 12:12:18 -04:00
hstore_gist.c Switch to CRC-32C in WAL and other places. 2014-11-04 11:39:48 +02:00
hstore_io.c Avoid some pnstrdup()s when constructing jsonb 2014-05-09 12:46:21 +03:00
hstore_op.c Create function prototype as part of PG_FUNCTION_INFO_V1 macro 2014-04-18 00:03:19 -04:00
hstore--1.0--1.1.sql
hstore--1.1--1.2.sql
hstore--1.2--1.3.sql
hstore--1.3.sql
hstore--unpackaged--1.0.sql Fix typos in some error messages thrown by extension scripts when fed to psql. 2014-08-25 18:30:37 +02:00
hstore.control
hstore.h pgindent run for 9.4 2014-05-06 12:12:18 -04:00
Makefile Switch to CRC-32C in WAL and other places. 2014-11-04 11:39:48 +02:00