$Header: -> $PostgreSQL Changes ...

testing $PostgreSQL$ tag

Daniel Convissor

Viktor Vislobokov

persistent_conn was left dangling after a disconnect in the
unnamed connection case, causing a subsequent disconnect to
crash the backend.

--with-openssl options.  This creates too much risk to pick up the wrong
directory accidentally (for example when there are lib64 directories), and
does not really help much with contemporary installation layouts.

was specified.

Ward's report that it can still happen in RC2 forces me to realize that
this is not a can't-happen condition after all, and that the compaction
code had better cope rather than panicking.

reported by Andrea Grassi.

they might be of a wider type.

insertion to reduce initialization time.

Vars created to fill subplan args lists.  This is an ancient error, going
back at least to 7.0, but is more easily triggered in 7.4 than before
because we no longer compare varlevelsup when deciding whether a Param
slot can be re-used.  Fixes bug reported by Klint Gore.

the hashclauses field of the parent HashJoin.  This avoids problems with
duplicated links to SubPlans in hash clauses, as per report from
Andrew Holm-Hansen.

depend on.

tree for CYCLE option; don't assume zeros are invalid values for sequence
fields other than increment_by; don't reset cache_value when not told to;
simplify code for testing whether to apply defaults.

back --infodir, which several automatic build environments expect to exist.
Add --without-docdir to prevent installation of documentation, which is
helpful for things like RPM that have their own method of installing
documentation.

Fixes compilation failure with --enable-thread-safety --with-perl and Perl
5.6.1.

large objects.  Dump all these in pg_dump; also add code to pg_dump
user-defined conversions.  Make psql's large object code rely on
the backend for inserting/deleting LOB comments, instead of trying to
hack pg_description directly.  Documentation and regression tests added.

Christopher Kings-Lynne, code reviewed by Tom

< A dash (-) marks changes that will appear in the upcoming 7.4 release.
> A dash (-) marks changes that will appear in the upcoming 7.5 release.
437c437
< * Use background process to write dirty shared buffers to disk
> * -Use background process to write dirty shared buffers to disk

< * -Allow elog() to return error codes, module name, file name, line
<   number, not just messages (Tom)
< * -Add error codes (Tom)
< * -Make error messages more consistent
40d35
< * -Add GUC log_statement_and_duration to print statement and >= min duration
51d45
< * -Allow easy display of usernames in a group
53d46
< * -Add start time to pg_stat_activity
55d47
< * -Have standalone backend read postgresql.conf (Tom)
59d50
< * -Allow CIDR format to be used in pg_hba.conf
74d64
< * -Add IPv6 capability to INET/CIDR types
77d66
< * -Change NUMERIC data type to use base 10,000 internally
82d70
< * -Add GUC variables to control floating number output digits (Pedro Ferreira)
90,92d77
< * -Allow current datestyle to restrict dates;  prevent month/day swapping
<   from making invalid dates valid
< * -Prevent month/day swapping of ISO dates to make invalid dates valid
102d86
< 	o -Allow arrays to be ORDER'ed
104d87
< 	o -Support construction of array result values in expressions (Joe)
128d110
< * -Remove Cyrillic recode support
146,147d127
< * -Allow CREATE INDEX zman_index ON test (date_trunc( 'day', zman ) datetime_ops)
<   fails index can't store constant parameters
155d134
< * -Add btree index support for reltime, tinterval, regproc (Tom)
157d135
< * -Certain indexes will not shrink, e.g. indexes on ever-increasing
161d138
< * -Allow LIKE indexing optimization for non-ASCII locales using special index
173d149
< * -Improve concurrency of hash indexes (Tom)
181d156
< * -Allow LIMIT/OFFSET to use expressions (Tom)
187d161
< * -Return proper effected tuple count from complex commands [return]
191d164
< * -Make a transaction-safe TRUNCATE (Rod)
196,197d168
< * -Allow UPDATE to use SET col = DEFAULT
< * -Add config variable to prevent auto-adding missing FROM-clause tables
199d169
< * -Have SELECT '13 minutes'::interval display zero seconds in ISO datestyle
224,225d193
< 	o -Add ALTER TABLE tab SET WITHOUT OIDS (Rod)
< 	o -Add ALTER SEQUENCE to modify min/max/increment/cache/cycle values
237d204
< 	o -Allow CLUSTER to cluster all tables (Alvaro Herrera)
248d214
< 	o -MOVE 0 should not move to end of cursor (Bruce)
252d217
< 	o -Allow cursors outside transactions
264,265d228
< 	o -Allow EXPLAIN EXECUTE to see prepared plans
<  	o -Allow SHOW of some non-modifiable variables, like pg_controldata
280d242
< 	o -Allow array declarations and other data types in PL/PgSQL DECLARE
282,283d243
< 	o -Make PL/PgSQL %TYPE schema-aware
< 	o -Allow PL/PgSQL to support array element assignment (Joe)
294,298d253
< * -Allow psql to show transaction status if backend protocol changes made
< * -Add schema, cast, and conversion backslash commands to psql (Christopher)
< * -Allow pg_dump to dump a specific schema (Neil Conway)
< * -Allow psql to do table completion for SELECT * FROM schema_part and
<   table completion for SELECT * FROM schema_name.
300,302d254
< * -Allow SSL-enabled clients to turn off SSL transfers
< * -Modify pg_get_triggerdef() to take a boolean to pretty-print,
<   and use that as part of pg_dump along with psql
327d278
< 	o -Add SQLSTATE
330d280
< 	o -Make casts work in variable initializations
334,336d283
< 	o -Allow multi-threaded use of SQLCA
< 	o -Understand structure definitions outside a declare section
< 	o -Allow :var[:index] or :var[<integer>] as cvariable for an array var
356d302
< * -Support statement-level triggers (Neil)
460,461d405
< * -Add checkpoint_min_warning postgresql.conf option to warn about checkpoints
<   that are too frequent (Bruce)
472,476d415
< * -Improve Subplan list handling
< * -Allow Subplans to use efficient joins(hash, merge) with upper variable
< * -Add hash for evaluating GROUP BY aggregates (Tom)
< * -Allow merge and hash joins on expressions not just simple variables (Tom)
< * -Make IN/NOT IN have similar performance to EXISTS/NOT EXISTS (Tom)
480d418
< * -Inline simple SQL functions to avoid overhead (Tom)
495d432
< * -Get faster regex() code from Henry Spencer <henry@zoo.utoronto.ca>
511,512d447
< * -Modify regression tests to prevent failures do to minor numeric rounding
< * -Add OpenBSD's getpeereid() call for local socket authentication
537,542d471
< 	o -Show transaction status in psql
< 	o -Allow binding of query parameters, support for prepared queries
< 	o -Remove hard-coded limits on user/db/password names
< 	o -Remove unused elements of startup packet (unused, tty, passlength)
< 	o -Fix COPY/fastpath protocol
< 	o -Error codes
544d472
< 	o -Special passing of binary values in platform-neutral format (bytea?)
547d474
< 	o -Report server version number, database encoding, client encoding

This first part of the background writer does no syncing at all.
It's only purpose is to keep the LRU heads clean so that regular
backends seldom to never have to call write().

Jan