rather than deleting them only to have to create more.  Steady state
is 2*CHECKPOINT_SEGMENTS + WAL_FILES + 1 segment files, which will
simply be renamed rather than constantly deleted and recreated.
To make this safe, added current XLOG file/offset number to page
header of XLOG pages, so that an un-overwritten page from an old
incarnation of a logfile can be reliably told from a valid page.
This change means that if you try to restart postmaster in a CVS-tip
database after installing the change, you'll get a complaint about
bad XLOG page magic number.  If you don't want to initdb, run
contrib/pg_resetxlog (and be sure you shut down the old postmaster
cleanly).

if there were no deletions to do.

predicates.  Per suggestion from Hiroshi.

that they have OIDs at all (the primary key for this table is indexrelid,
not OID).  Simplify overly complex query to get name of primary key.

in GetSnapshotData, GetNewTransactionId, CommitTransaction, AbortTransaction,
etc.  Correct race condition in transaction status testing in
HeapTupleSatisfiesVacuum --- this wasn't important for old VACUUM with
exclusive lock on its table, but it sure is important now.  All per
pghackers discussion 7/11/01 and 7/12/01.

Martijn van Oosterhout

since the added qual could change the set of rows that get past the
LIMIT.  Per discussion on pgsql-sql 7/15/01.

Note: I didn't force an initdb, figuring that one today was enough.
However, there is a new function in pg_proc.h, and pg_dump won't be
able to dump partial indexes until you add that function.

per previous discussion on pghackers.  Most of the duplicate code in
different AMs' ambuild routines has been moved out to a common routine
in index.c; this means that all index types now do the right things about
inserting recently-dead tuples, etc.  (I also removed support for EXTEND
INDEX in the ambuild routines, since that's about to go away anyway, and
it cluttered the code a lot.)  The retail indextuple deletion routines have
been replaced by a "bulk delete" routine in which the indexscan is inside
the access method.  I haven't pushed this change as far as it should go yet,
but it should allow considerable simplification of the internal bookkeeping
for deletions.  Also, add flag columns to pg_am to eliminate various
hardcoded tests on AM OIDs, and remove unused pg_am columns.

Fix rtree and gist index types to not attempt to store NULLs; before this,
gist usually crashed, while rtree managed not to crash but computed wacko
bounding boxes for NULL entries (which might have had something to do with
the performance problems we've heard about occasionally).

Add AtEOXact routines to hash, rtree, and gist, all of which have static
state that needs to be reset after an error.  We discovered this need long
ago for btree, but missed the other guys.

Oh, one more thing: concurrent VACUUM is now the default.

as predictable as it used to be, due to recycling of free space with
new VACUUM.

accordingly.

absolute paths of the source tree in the po files.  Also, run msgfmt with
-c option in maintainer-check.

* Make n of CHAR(n)/VARCHAR(n) the number of letters, not bytes

null terminated strings.  The FE/BE protocol sends in some cases null
terminated strings to the client.  The docs for the FE/BE protocol state
that there is no limit on the size of a null terminated string sent to
the client and a client should be coded using an expanding buffer to
deal with large strings.  The old code did not do this and gave an error
if a null terminated string was greater than either 4 or 8K.  It appears
that with the advent of TOAST very long SQL statements are becoming more
common, and apparently some error messages from the backend include the
SQL statement thus easily exceeding the 8K limit in the old code.

In fixing I also cleaned up some calls in the JDBC fastpath code that
were not doing character set conversion under multibyte, and removed
some methods that were no longer needed.  I also removed a potential
threading problem with a shared variable that was being used in
Connection.java.

Thanks to Steve Wampler for discovering the problem and sending the
initial diffs that were the basis of this patch.

thanks,
--Barry

because index locking issues are not handled correctly yet.  Need to go
work on the index AMs next.

From Vince Vielhaber.

validity checking rules for VACUUM.  Make some other rearrangements of the
VACUUM code to allow more code to be shared between full and lazy VACUUM.
Minor code cleanups and added comments for TransactionId manipulations.