comment line where output as too long, and update typedefs for /lib
directory. Also fix case where identifiers were used as variable names
in the backend, but as typedefs in ecpg (favor the backend for
indenting).
Backpatch to 8.1.X.
tuple in-place, but instead passes back an all-new tuple structure if
any changes are needed. This is a much cleaner and more robust solution
for the bug discovered by Alexey Beschiokov; accordingly, revert the
quick hack I installed yesterday.
With this change, HeapTupleData.t_datamcxt is no longer needed; will
remove it in a separate commit in HEAD only.
whenever we generate a new OID. This prevents occasional duplicate-OID
errors that can otherwise occur once the OID counter has wrapped around.
Duplicate relfilenode values are also checked for when creating new
physical files. Per my recent proposal.
convention for isnull flags. Also, remove the useless InsertIndexResult
return struct from index AM aminsert calls --- there is no reason for
the caller to know where in the index the tuple was inserted, and we
were wasting a palloc cycle per insert to deliver this uninteresting
value (plus nontrivial complexity in some AMs).
I forced initdb because of the change in the signature of the aminsert
routines, even though nothing really looks at those pg_proc entries...
a tuple are being accessed via ExecEvalVar and the attcacheoff shortcut
isn't usable (due to nulls and/or varlena columns). To do this, cache
Datums extracted from a tuple in the associated TupleTableSlot.
Also some code cleanup in and around the TupleTable handling.
Atsushi Ogawa with some kibitzing by Tom Lane.
now are supposed to take some kind of lock on an index whenever you
are going to access the index contents, rather than relying only on a
lock on the parent table.
1. Solve the problem of not having TOAST references hiding inside composite
values by establishing the rule that toasting only goes one level deep:
a tuple can contain toasted fields, but a composite-type datum that is
to be inserted into a tuple cannot. Enforcing this in heap_formtuple
is relatively cheap and it avoids a large increase in the cost of running
the tuptoaster during final storage of a row.
2. Fix some interesting problems in expansion of inherited queries that
reference whole-row variables. We never really did this correctly before,
but it's now relatively painless to solve by expanding the parent's
whole-row Var into a RowExpr() selecting the proper columns from the
child.
If you dike out the preventive check in CheckAttributeType(),
composite-type columns now seem to actually work. However, we surely
cannot ship them like this --- without I/O for composite types, you
can't get pg_dump to dump tables containing them. So a little more
work still to do.
loop over the fields instead of a loop around heap_getattr. This is
considerably faster (O(N) instead of O(N^2)) when there are nulls or
varlena fields, since those prevent use of attcacheoff. Replace loops
over heap_getattr with heap_deformtuple in situations where all or most
of the fields have to be fetched, such as printtup and tuptoaster.
Profiling done more than a year ago shows that this should be a nice
win for situations involving many-column tables.
pghackers proposal of 8-Nov. All the existing cross-type comparison
operators (int2/int4/int8 and float4/float8) have appropriate support.
The original proposal of storing the right-hand-side datatype as part of
the primary key for pg_amop and pg_amproc got modified a bit in the event;
it is easier to store zero as the 'default' case and only store a nonzero
when the operator is actually cross-type. Along the way, remove the
long-since-defunct bigbox_ops operator class.
Remove the 'strategy map' code, which was a large amount of mechanism
that no longer had any use except reverse-mapping from procedure OID to
strategy number. Passing the strategy number to the index AM in the
first place is simpler and faster.
This is a preliminary step in planned support for cross-datatype index
operations. I'm committing it now since the ScanKeyEntryInitialize()
API change touches quite a lot of files, and I want to commit those
changes before the tree drifts under me.
(overlaying low byte of page size) and add HEAP_HASOID bit to t_infomask,
per earlier discussion. Simplify scheme for overlaying fields in tuple
header (no need for cmax to live in more than one place). Don't try to
clear infomask status bits in tqual.c --- not safe to do it there. Don't
try to force output table of a SELECT INTO to have OIDs, either. Get rid
of unnecessarily complex three-state scheme for TupleDesc.tdhasoids, which
has already caused one recent failure. Improve documentation.
The local buffer manager is no longer used for newly-created relations
(unless they are TEMP); a new non-TEMP relation goes through the shared
bufmgr and thus will participate normally in checkpoints. But TEMP relations
use the local buffer manager throughout their lifespan. Also, operations
in TEMP relations are not logged in WAL, thus improving performance.
Since it's no longer necessary to fsync relations as they move out of the
local buffers into shared buffers, quite a lot of smgr.c/md.c/fd.c code
is no longer needed and has been removed: there's no concept of a dirty
relation anymore in md.c/fd.c, and we never fsync anything but WAL.
Still TODO: improve local buffer management algorithms so that it would
be reasonable to increase NLocBuffer.
bitmap, if present).
Per Tom Lane's suggestion the information whether a tuple has an oid
or not is carried in the tuple descriptor. For debugging reasons
tdhasoid is of type char, not bool. There are predefined values for
WITHOID, WITHOUTOID and UNDEFOID.
This patch has been generated against a cvs snapshot from last week
and I don't expect it to apply cleanly to current sources. While I
post it here for public review, I'm working on a new version against a
current snapshot. (There's been heavy activity recently; hope to
catch up some day ...)
This is a long patch; if it is too hard to swallow, I can provide it
in smaller pieces:
Part 1: Accessor macros
Part 2: tdhasoid in TupDesc
Part 3: Regression test
Part 4: Parameter withoid to heap_addheader
Part 5: Eliminate t_oid from HeapTupleHeader
Part 2 is the most hairy part because of changes in the executor and
even in the parser; the other parts are straightforward.
Up to part 4 the patched postmaster stays binary compatible to
databases created with an unpatched version. Part 5 is small (100
lines) and finally breaks compatibility.
Manfred Koizar
where the latter is made slightly larger to allow for in-memory tuples
containing resjunk attributes. Responds to today's complaint that one
cannot UPDATE a table containing the allegedly-legal maximum number of
columns.
Also, apply Manfred Koizar's recent patch to avoid extra alignment padding
when there is a null bitmap. This saves bytes in some cases while not
creating any backward-compatibility problem AFAICS.
transaction, so as to avoid returning them out of the index AM. Saves
repeated heap_fetch operations on frequently-updated rows. Also detect
queries on unique keys (equality to all columns of a unique index), and
don't bother continuing scan once we have found first match.
Killing is implemented in the btree and hash AMs, but not yet in rtree
or gist, because there isn't an equally convenient place to do it in
those AMs (the outer amgetnext routine can't do it without re-pinning
the index page).
Did some small cleanup on APIs of HeapTupleSatisfies, heap_fetch, and
index_insert to make this a little easier.
in snapshots, per my proposal of a few days ago. Also, tweak heapam.c
routines (heap_insert, heap_update, heap_delete, heap_mark4update) to
be passed the command ID to use, instead of doing GetCurrentCommandID.
For catalog updates they'll still get passed current command ID, but
for updates generated from the main executor they'll get passed the
command ID saved in the snapshot the query is using. This should fix
some corner cases associated with functions and triggers that advance
current command ID while an outer query is still in progress.
yesterday's proposal to pghackers. Also remove unnecessary parameters
to heap_beginscan, heap_rescan. I modified pg_proc.h to reflect the
new numbers of parameters for the AM interface routines, but did not
force an initdb because nothing actually looks at those fields.
(current as of a few hours ago.)
This patch:
1. Adds PG_GETARG_xxx_P_SLICE() macros and associated support routines.
2. Adds routines in src/backend/access/tuptoaster.c for fetching only
necessary chunks of a toasted value. (Modelled on latest changes to
assume chunks are returned in order).
3. Amends text_substr and bytea_substr to use new methods. It now
handles multibyte cases -and should still lead to a performance
improvement in the multibyte case where the substring is near the
beginning of the string.
4. Added new command: ALTER TABLE tabname ALTER COLUMN colname SET
STORAGE {PLAIN | EXTERNAL | EXTENDED | MAIN} to parser and documented in
alter-table.sgml. (NB I used ColId as the item type for the storage
mode string, rather than a new production - I hope this makes sense!).
All this does is sets attstorage for the specified column.
4. AlterTableAlterColumnStatistics is now AlterTableAlterColumnFlags and
handles both statistics and storage (it uses the subtype code to
distinguish). The previous version of my patch also re-arranged other
code in backend/commands/command.c but I have dropped that from this
patch.(I plan to return to it separately).
5. Documented new macros (and also the PG_GETARG_xxx_P_COPY macros) in
xfunc.sgml. ref/alter_table.sgml also contains documentation for ALTER
COLUMN SET STORAGE.
John Gray
mess up after an aborted VACUUM FULL, per today's pghackers discussion.
Add a suitable HeapTupleSatisfiesToast routine. Remove useless special-
case test in HeapTupleSatisfiesVisibility macro for xmax =
BootstrapTransactionId; perhaps that was needed at one time, but it's
a waste of cycles now, not to mention actively wrong for SnapshotAny.
Along the way, add some much-needed comments to tqual.c, and simplify
toast_fetch_datum, which no longer needs to assume it may see chunks
out-of-order.
default, but OIDS are removed from many system catalogs that don't need them.
Some interesting side effects: TOAST pointers are 20 bytes not 32 now;
pg_description has a three-column key instead of one.
Bugs fixed in passing: BINARY cursors work again; pg_class.relhaspkey
has some usefulness; pg_dump dumps comments on indexes, rules, and
triggers in a valid order.
initdb forced.
a separate statement (though it can still be invoked as part of VACUUM, too).
pg_statistic redesigned to be more flexible about what statistics are
stored. ANALYZE now collects a list of several of the most common values,
not just one, plus a histogram (not just the min and max values). Random
sampling is used to make the process reasonably fast even on very large
tables. The number of values and histogram bins collected is now
user-settable via an ALTER TABLE command.
There is more still to do; the new stats are not being used everywhere
they could be in the planner. But the remaining changes for this project
should be localized, and the behavior is already better than before.
A not-very-related change is that sorting now makes use of btree comparison
routines if it can find one, rather than invoking '<' twice.
compressed storage works perfectly well. Might as well have a coherent
strategy for applying it, rather than the haphazard store-what-you-get
approach that was in the code before. The strategy I've set up here is
to attempt compression of any compressible index value exceeding
BLCKSZ/16, or about 500 bytes by default.
bothering to check the return value --- which meant that in case the
update or delete failed because of a concurrent update, you'd not find
out about it, except by observing later that the transaction produced
the wrong outcome. There are now subroutines simple_heap_update and
simple_heap_delete that should be used anyplace that you're not prepared
to do the full nine yards of coping with concurrent updates. In
practice, that seems to mean absolutely everywhere but the executor,
because *noplace* else was checking.
source, due to addition of header overhead), store it as plain data
rather than pseudo-compressed data. This saves a few microseconds when
reading it out, but much more importantly guarantees that the toaster
won't actually expand tuples that contain incompressible data. That's
essential to avoid 'Tuple too big' failures with large objects.
trying to toast tuples inserted into toast tables! Fix is two-pronged:
first, ensure all columns of a toast table are marked attstorage='p',
and second, alter the target chunk size so that it's less than the
threshold for trying to toast a tuple. (Code tried to do that but the
expression was wrong.) A few cosmetic cleanups in tuptoaster too.
NOTE: initdb forced due to change in toaster chunk-size.
Bruce Momjian
Tom Lane
PostgreSQL Daemon
Jan Wieck