equality checks it applies, instead of a random dependence on whatever
operators might be named "=". The equality operators will now be selected
from the opfamily of the unique index that the FK constraint depends on to
enforce uniqueness of the referenced columns; therefore they are certain to be
consistent with that index's notion of equality. Among other things this
should fix the problem noted awhile back that pg_dump may fail for foreign-key
constraints on user-defined types when the required operators aren't in the
search path. This also means that the former warning condition about "foreign
key constraint will require costly sequential scans" is gone: if the
comparison condition isn't indexable then we'll reject the constraint
entirely. All per past discussions.
Along the way, make the RI triggers look into pg_constraint for their
information, instead of using pg_trigger.tgargs; and get rid of the always
error-prone fixed-size string buffers in ri_triggers.c in favor of building up
the RI queries in StringInfo buffers.
initdb forced due to columns added to pg_constraint and pg_trigger.
< * Merge xmin/xmax/cmin/cmax back into three header fields
<
< Before subtransactions, there used to be only three fields needed to
< store these four values. This was possible because only the current
< transaction looks at the cmin/cmax values. If the current transaction
< created and expired the row the fields stored where xmin (same as
< xmax), cmin, cmax, and if the transaction was expiring a row from a
< another transaction, the fields stored were xmin (cmin was not
< needed), xmax, and cmax. Such a system worked because a transaction
< could only see rows from another completed transaction. However,
< subtransactions can see rows from outer transactions, and once the
< subtransaction completes, the outer transaction continues, requiring
< the storage of all four fields. With subtransactions, an outer
< transaction can create a row, a subtransaction expire it, and when the
< subtransaction completes, the outer transaction still has to have
< proper visibility of the row's cmin, for example, for cursors.
<
< One possible solution is to create a phantom cid which represents a
< cmin/cmax pair and is stored in local memory. Another idea is to
< store both cmin and cmax only in local memory.
<
> * -Merge xmin/xmax/cmin/cmax back into three header fields
< * Consider placing all sequences in a single table, now that system
< tables are full transactional
> * Consider placing all sequences in a single table
already collected in the current transaction; this allows plpgsql functions to
watch for stats updates even though they are confined to a single transaction.
Use this instead of the previous kluge involving pg_stat_file() to wait for
the stats collector to update in the stats regression test. Internally,
decouple storage of stats snapshots from transaction boundaries; they'll
now stick around until someone calls pgstat_clear_snapshot --- which xact.c
still does at transaction end, to maintain the previous behavior. This makes
the logic a lot cleaner, at the price of a couple dozen cycles per transaction
exit.
<P>USA saving time changes are included in PostgreSQL release 8.0.[4+],
and all later major releases, e.g. 8.1. Canada and Western Australia
changes are included in 8.0.[10+], 8.1.[6+], and all later major
releases. PostgreSQL releases prior to 8.0 use the operating system's
timezone database for daylight saving information.</P>
Standard English uses "may", "can", and "might" in different ways:
may - permission, "You may borrow my rake."
can - ability, "I can lift that log."
might - possibility, "It might rain today."
Unfortunately, in conversational English, their use is often mixed, as
in, "You may use this variable to do X", when in fact, "can" is a better
choice. Similarly, "It may crash" is better stated, "It might crash".
Standard English uses "may", "can", and "might" in different ways:
may - permission, "You may borrow my rake."
can - ability, "I can lift that log."
might - possibility, "It might rain today."
Unfortunately, in conversational English, their use is often mixed, as
in, "You may use this variable to do X", when in fact, "can" is a better
choice. Similarly, "It may crash" is better stated, "It might crash".
Standard English uses "may", "can", and "might" in different ways:
may - permission, "You may borrow my rake."
can - ability, "I can lift that log."
might - possibility, "It might rain today."
Unfortunately, in conversational English, their use is often mixed, as
in, "You may use this variable to do X", when in fact, "can" is a better
choice. Similarly, "It may crash" is better stated, "It might crash".
Also update two error messages mentioned in the documenation to match.
In this case extractQuery should returns -1 as nentries. This changes
prototype of extractQuery method to use int32* instead of uint32* for
nentries argument.
Based on that gincostestimate may see two corner cases: nothing will be found
or seqscan should be used.
Per proposal at http://archives.postgresql.org/pgsql-hackers/2007-01/msg01581.php
PS tsearch_core patch should be sightly modified to support changes, but I'm
waiting a verdict about reviewing of tsearch_core patch.
>
> * Add REINDEX CONCURRENTLY, like CREATE INDEX CONCURRENTLY
>
> This is difficult because you must upgrade to an exclusive table lock
> to replace the existing index file. CREATE INDEX CONCURRENTLY does not
> have this complication. This would allow index compaction without
> downtime.
more, and standard_conforming_strings less, because in the future non-E
strings will not treat backslashes specially.
Also use E'' strings where backslashes are used in examples. (The
existing examples would have drawn warnings.)
Backpatch to 8.2.X.
Peter Eisentraut
Tom Lane
Bruce Momjian
Neil Conway
Teodor Sigaev