Unlike Btree-based LIKE optimization, this works for non-left-anchored
search patterns. The effectiveness of the search depends on how many
trigrams can be extracted from the pattern. (The worst case, with no
trigrams, degrades to a full-table scan, so this isn't a panacea. But
it can be very useful.)
Alexander Korotkov, reviewed by Jan Urbanski
contrib/intarray's gettoken() uses a fixed-size buffer to collect an
integer's digits, and did not guard against overrunning the buffer.
This is at least a backend crash risk, and in principle might allow
arbitrary code execution. The code didn't check for overflow of the
integer value either, which while not presenting a crash risk was still
bad.
Thanks to Apple Inc's security team for reporting this issue and supplying
the fix.
Security: CVE-2010-4015
This is still pretty rough - among other things, the documentation
needs work, and the messages need a visit from the style police -
but this gets the basic framework in place.
KaiGai Kohei
Reduce #includes to minimum actually needed; in particular include
postgres_fe.h not postgres.h, so as to stop build failures on some
platforms.
Use get_progname() instead of hardwired program name; improve error
checking for command line syntax; bring error messages into line with
style guidelines; include strerror result in die() cases.
Un-break Windows build (I hope) by making the HAVE_FSYNC_WRITETHROUGH
code match the backend. Fix incorrect program help message. static-ize
all functions.
Actually rename the program, rather than just claiming we did. Hook it
into the build system. Get rid of useless dependency on libpq. Clean up
#include list and messy whitespace.
In particular, make hstore @> '' succeed for all hstores, likewise
hstore ?& '{}'. Previously the results were inconsistent and could
depend on whether you were using a GiST index, GIN index, or seqscan.
This applies the fix for bug #5784 to remaining places where we wish
to reject nulls in user-supplied arrays. In all these places, there's
no reason not to allow a null bitmap to be present, so long as none of
the current elements are actually null.
I did not change some other places where we are looking at system catalog
entries or aggregate transition values, as the presence of a null bitmap
in such an array would be suspicious.
The array containment operators now behave per mathematical expectation
for empty arrays (ie, an empty array is contained in anything).
Both these operators and the query_int operators now work as expected in
GiST and GIN index searches, rather than having corner cases where the
index searches gave different answers.
Also, fix unexpected failures where the operators would claim that an array
contained nulls, when in fact there was no longer any null present (similar
to bug #5784). The restriction to not have nulls is still there, as
removing it would take a lot of added code complexity and probably slow
things down significantly.
Also, remove the arbitrary restriction to 1-D arrays; unlike the other
restriction, this was buying us nothing performance-wise.
Assorted cosmetic improvements and marginal performance improvements, too.
up relations, but rather order old/new relations and use the same array
index value for both. This should speed up pg_upgrade for databases
with many relations.
which is stored in pg_largeobject_metadata.
No backpatch to 9.0 because you can't migrate from 9.0 to 9.0 with the
same catversion (because of tablespace conflict), and a pre-9.0
migration to 9.0 has not large object permissions to migrate.
Toast tables have identical pg_class.oid and pg_class.relfilenode, but
for clarity it is good to preserve the pg_class.oid.
Update comments regarding what is preserved, and do some
variable/function renaming for clarity.
Per my recent proposal(s). Null key datums can now be returned by
extractValue and extractQuery functions, and will be stored in the index.
Also, placeholder entries are made for indexable items that are NULL or
contain no keys according to extractValue. This means that the index is
now always complete, having at least one entry for every indexed heap TID,
and so we can get rid of the prohibition on full-index scans. A full-index
scan is implemented much the same way as partial-match scans were already:
we build a bitmap representing all the TIDs found in the index, and then
drive the results off that.
Also, introduce a concept of a "search mode" that can be requested by
extractQuery when the operator requires matching to empty items (this is
just as cheap as matching to a single key) or requires a full index scan
(which is not so cheap, but it sure beats failing or giving wrong answers).
The behavior remains backward compatible for opclasses that don't return
any null keys or request a non-default search mode.
Using these features, we can now make the GIN index opclass for anyarray
behave in a way that matches the actual anyarray operators for &&, <@, @>,
and = ... which it failed to do before in assorted corner cases.
This commit fixes the core GIN code and ginarrayprocs.c, updates the
documentation, and adds some simple regression test cases for the new
behaviors using the array operators. The tsearch and contrib GIN opclass
support functions still need to be looked over and probably fixed.
Another thing I intend to fix separately is that this is pretty inefficient
for cases where more than one scan condition needs a full-index search:
we'll run duplicate GinScanEntrys, each one of which builds a large bitmap.
There is some existing logic to merge duplicate GinScanEntrys but it needs
refactoring to make it work for entries belonging to different scan keys.
Note that most of gin.h has been split out into a new file gin_private.h,
so that gin.h doesn't export anything that's not supposed to be used by GIN
opclasses or the rest of the backend. I did quite a bit of other code
beautification work as well, mostly fixing comments and choosing more
appropriate names for things.
Tom Lane
Bruce Momjian
Robert Haas