Upthread I wrote: > -A possible TODO item is to teach pg_upgrade not to link FSMs for > small heaps. I haven't look into the feasibility of that, however.
This turned out to be relatively light weight (0002 attached). I had to add relkind to the RelInfo struct and save the size of each heap as its transferred. The attached SQL script will setup a couple test cases to demonstrate pg_upgrade. Installations with large numbers of small tables will be able to see space savings right away. For 0001, I adjusted the README and docs, and also made some cosmetic improvements to the code, mostly in the comments. I've set the commitfest entry back to 'needs review' One thing I noticed is that one behavior on master hasn't changed: System catalogs created during bootstrap still have a FSM if they have any data. Possibly related, catalogs also have a VM even if they have no data at all. This isn't anything to get excited about, but it would be nice to investigate, at least so it can be documented. A cursory dig hasn't found the cause, but I'll keep doing that as time permits. -John Naylor
From 428b56e12e3f5d2bd8fc81c9fb5fe7169e9da580 Mon Sep 17 00:00:00 2001
From: John Naylor <jcnay...@gmail.com>
Date: Wed, 31 Oct 2018 14:26:38 +0700
Subject: [PATCH v7 1/2] Avoid creation of the free space map for small tables.
The FSM isn't created if the heap has fewer than 8 blocks. If the last
known good block has insufficient space, try every block before extending
the heap.
If a heap with a FSM is truncated back to below the threshold, the FSM
stays around and can be used as usual.
---
contrib/pageinspect/expected/page.out | 77 +++----
contrib/pageinspect/sql/page.sql | 33 +--
doc/src/sgml/storage.sgml | 3 +-
src/backend/access/brin/brin.c | 2 +-
src/backend/access/brin/brin_pageops.c | 8 +-
src/backend/access/heap/hio.c | 61 ++++--
src/backend/commands/vacuumlazy.c | 17 +-
src/backend/storage/freespace/README | 11 +-
src/backend/storage/freespace/freespace.c | 234 +++++++++++++++++++++-
src/backend/storage/freespace/indexfsm.c | 4 +-
src/include/storage/freespace.h | 6 +-
11 files changed, 360 insertions(+), 96 deletions(-)
diff --git a/contrib/pageinspect/expected/page.out b/contrib/pageinspect/expected/page.out
index 3fcd9fbe6d..83e5910453 100644
--- a/contrib/pageinspect/expected/page.out
+++ b/contrib/pageinspect/expected/page.out
@@ -1,48 +1,69 @@
CREATE EXTENSION pageinspect;
-CREATE TABLE test1 (a int, b int);
-INSERT INTO test1 VALUES (16777217, 131584);
-VACUUM test1; -- set up FSM
+CREATE TABLE test_rel_forks (a int);
+-- Make sure there are enough blocks in the heap for the FSM to be created.
+INSERT INTO test_rel_forks SELECT g from generate_series(1,10000) g;
+-- set up FSM and VM
+VACUUM test_rel_forks;
-- The page contents can vary, so just test that it can be read
-- successfully, but don't keep the output.
-SELECT octet_length(get_raw_page('test1', 'main', 0)) AS main_0;
+SELECT octet_length(get_raw_page('test_rel_forks', 'main', 0)) AS main_0;
main_0
--------
8192
(1 row)
-SELECT octet_length(get_raw_page('test1', 'main', 1)) AS main_1;
-ERROR: block number 1 is out of range for relation "test1"
-SELECT octet_length(get_raw_page('test1', 'fsm', 0)) AS fsm_0;
+SELECT octet_length(get_raw_page('test_rel_forks', 'main', 100)) AS main_100;
+ERROR: block number 100 is out of range for relation "test_rel_forks"
+SELECT octet_length(get_raw_page('test_rel_forks', 'fsm', 0)) AS fsm_0;
fsm_0
-------
8192
(1 row)
-SELECT octet_length(get_raw_page('test1', 'fsm', 1)) AS fsm_1;
- fsm_1
--------
- 8192
-(1 row)
-
-SELECT octet_length(get_raw_page('test1', 'vm', 0)) AS vm_0;
+SELECT octet_length(get_raw_page('test_rel_forks', 'fsm', 10)) AS fsm_10;
+ERROR: block number 10 is out of range for relation "test_rel_forks"
+SELECT octet_length(get_raw_page('test_rel_forks', 'vm', 0)) AS vm_0;
vm_0
------
8192
(1 row)
-SELECT octet_length(get_raw_page('test1', 'vm', 1)) AS vm_1;
-ERROR: block number 1 is out of range for relation "test1"
+SELECT octet_length(get_raw_page('test_rel_forks', 'vm', 1)) AS vm_1;
+ERROR: block number 1 is out of range for relation "test_rel_forks"
SELECT octet_length(get_raw_page('xxx', 'main', 0));
ERROR: relation "xxx" does not exist
-SELECT octet_length(get_raw_page('test1', 'xxx', 0));
+SELECT octet_length(get_raw_page('test_rel_forks', 'xxx', 0));
ERROR: invalid fork name
HINT: Valid fork names are "main", "fsm", "vm", and "init".
-SELECT get_raw_page('test1', 0) = get_raw_page('test1', 'main', 0);
+SELECT * FROM fsm_page_contents(get_raw_page('test_rel_forks', 'fsm', 0));
+ fsm_page_contents
+-------------------
+ 0: 192 +
+ 1: 192 +
+ 3: 192 +
+ 7: 192 +
+ 15: 192 +
+ 31: 192 +
+ 63: 192 +
+ 127: 192 +
+ 255: 192 +
+ 511: 192 +
+ 1023: 192 +
+ 2047: 192 +
+ 4095: 192 +
+ fp_next_slot: 0 +
+
+(1 row)
+
+SELECT get_raw_page('test_rel_forks', 0) = get_raw_page('test_rel_forks', 'main', 0);
?column?
----------
t
(1 row)
+DROP TABLE test_rel_forks;
+CREATE TABLE test1 (a int, b int);
+INSERT INTO test1 VALUES (16777217, 131584);
SELECT pagesize, version FROM page_header(get_raw_page('test1', 0));
pagesize | version
----------+---------
@@ -62,26 +83,6 @@ SELECT tuple_data_split('test1'::regclass, t_data, t_infomask, t_infomask2, t_bi
{"\\x01000001","\\x00020200"}
(1 row)
-SELECT * FROM fsm_page_contents(get_raw_page('test1', 'fsm', 0));
- fsm_page_contents
--------------------
- 0: 254 +
- 1: 254 +
- 3: 254 +
- 7: 254 +
- 15: 254 +
- 31: 254 +
- 63: 254 +
- 127: 254 +
- 255: 254 +
- 511: 254 +
- 1023: 254 +
- 2047: 254 +
- 4095: 254 +
- fp_next_slot: 0 +
-
-(1 row)
-
DROP TABLE test1;
-- check that using any of these functions with a partitioned table or index
-- would fail
diff --git a/contrib/pageinspect/sql/page.sql b/contrib/pageinspect/sql/page.sql
index 8ac9991837..ee811759d5 100644
--- a/contrib/pageinspect/sql/page.sql
+++ b/contrib/pageinspect/sql/page.sql
@@ -1,26 +1,35 @@
CREATE EXTENSION pageinspect;
-CREATE TABLE test1 (a int, b int);
-INSERT INTO test1 VALUES (16777217, 131584);
+CREATE TABLE test_rel_forks (a int);
+-- Make sure there are enough blocks in the heap for the FSM to be created.
+INSERT INTO test_rel_forks SELECT g from generate_series(1,10000) g;
-VACUUM test1; -- set up FSM
+-- set up FSM and VM
+VACUUM test_rel_forks;
-- The page contents can vary, so just test that it can be read
-- successfully, but don't keep the output.
-SELECT octet_length(get_raw_page('test1', 'main', 0)) AS main_0;
-SELECT octet_length(get_raw_page('test1', 'main', 1)) AS main_1;
+SELECT octet_length(get_raw_page('test_rel_forks', 'main', 0)) AS main_0;
+SELECT octet_length(get_raw_page('test_rel_forks', 'main', 100)) AS main_100;
-SELECT octet_length(get_raw_page('test1', 'fsm', 0)) AS fsm_0;
-SELECT octet_length(get_raw_page('test1', 'fsm', 1)) AS fsm_1;
+SELECT octet_length(get_raw_page('test_rel_forks', 'fsm', 0)) AS fsm_0;
+SELECT octet_length(get_raw_page('test_rel_forks', 'fsm', 10)) AS fsm_10;
-SELECT octet_length(get_raw_page('test1', 'vm', 0)) AS vm_0;
-SELECT octet_length(get_raw_page('test1', 'vm', 1)) AS vm_1;
+SELECT octet_length(get_raw_page('test_rel_forks', 'vm', 0)) AS vm_0;
+SELECT octet_length(get_raw_page('test_rel_forks', 'vm', 1)) AS vm_1;
SELECT octet_length(get_raw_page('xxx', 'main', 0));
-SELECT octet_length(get_raw_page('test1', 'xxx', 0));
+SELECT octet_length(get_raw_page('test_rel_forks', 'xxx', 0));
+
+SELECT * FROM fsm_page_contents(get_raw_page('test_rel_forks', 'fsm', 0));
+
+SELECT get_raw_page('test_rel_forks', 0) = get_raw_page('test_rel_forks', 'main', 0);
-SELECT get_raw_page('test1', 0) = get_raw_page('test1', 'main', 0);
+DROP TABLE test_rel_forks;
+
+CREATE TABLE test1 (a int, b int);
+INSERT INTO test1 VALUES (16777217, 131584);
SELECT pagesize, version FROM page_header(get_raw_page('test1', 0));
@@ -29,8 +38,6 @@ SELECT page_checksum(get_raw_page('test1', 0), 0) IS NOT NULL AS silly_checksum_
SELECT tuple_data_split('test1'::regclass, t_data, t_infomask, t_infomask2, t_bits)
FROM heap_page_items(get_raw_page('test1', 0));
-SELECT * FROM fsm_page_contents(get_raw_page('test1', 'fsm', 0));
-
DROP TABLE test1;
-- check that using any of these functions with a partitioned table or index
diff --git a/doc/src/sgml/storage.sgml b/doc/src/sgml/storage.sgml
index 8ef2ac8010..784cc22f4d 100644
--- a/doc/src/sgml/storage.sgml
+++ b/doc/src/sgml/storage.sgml
@@ -590,7 +590,8 @@ tuple would otherwise be too big.
<indexterm><primary>FSM</primary><see>Free Space Map</see></indexterm>
<para>
-Each heap and index relation, except for hash indexes, has a Free Space Map
+Each heap relation, unless it is very small, and each index relation,
+except for hash indexes, has a Free Space Map
(FSM) to keep track of available space in the relation. It's stored
alongside the main relation data in a separate relation fork, named after the
filenode number of the relation, plus a <literal>_fsm</literal> suffix. For example,
diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index e95fbbcea7..7c5b1af764 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -1148,7 +1148,7 @@ terminate_brin_buildstate(BrinBuildState *state)
freespace = PageGetFreeSpace(page);
blk = BufferGetBlockNumber(state->bs_currentInsertBuf);
ReleaseBuffer(state->bs_currentInsertBuf);
- RecordPageWithFreeSpace(state->bs_irel, blk, freespace);
+ RecordPageWithFreeSpace(state->bs_irel, blk, freespace, InvalidBlockNumber);
FreeSpaceMapVacuumRange(state->bs_irel, blk, blk + 1);
}
diff --git a/src/backend/access/brin/brin_pageops.c b/src/backend/access/brin/brin_pageops.c
index 040cb62e55..70d93878ba 100644
--- a/src/backend/access/brin/brin_pageops.c
+++ b/src/backend/access/brin/brin_pageops.c
@@ -310,7 +310,7 @@ brin_doupdate(Relation idxrel, BlockNumber pagesPerRange,
if (extended)
{
- RecordPageWithFreeSpace(idxrel, newblk, freespace);
+ RecordPageWithFreeSpace(idxrel, newblk, freespace, InvalidBlockNumber);
FreeSpaceMapVacuumRange(idxrel, newblk, newblk + 1);
}
@@ -461,7 +461,7 @@ brin_doinsert(Relation idxrel, BlockNumber pagesPerRange,
if (extended)
{
- RecordPageWithFreeSpace(idxrel, blk, freespace);
+ RecordPageWithFreeSpace(idxrel, blk, freespace, InvalidBlockNumber);
FreeSpaceMapVacuumRange(idxrel, blk, blk + 1);
}
@@ -654,7 +654,7 @@ brin_page_cleanup(Relation idxrel, Buffer buf)
/* Measure free space and record it */
RecordPageWithFreeSpace(idxrel, BufferGetBlockNumber(buf),
- br_page_get_freespace(page));
+ br_page_get_freespace(page), InvalidBlockNumber);
}
/*
@@ -895,7 +895,7 @@ brin_initialize_empty_new_buffer(Relation idxrel, Buffer buffer)
* pages whose FSM records were forgotten in a crash.
*/
RecordPageWithFreeSpace(idxrel, BufferGetBlockNumber(buffer),
- br_page_get_freespace(page));
+ br_page_get_freespace(page), InvalidBlockNumber);
}
diff --git a/src/backend/access/heap/hio.c b/src/backend/access/heap/hio.c
index b8b5871559..ff13c03083 100644
--- a/src/backend/access/heap/hio.c
+++ b/src/backend/access/heap/hio.c
@@ -24,6 +24,8 @@
#include "storage/lmgr.h"
#include "storage/smgr.h"
+/*#define TRACE_TARGETBLOCK */
+
/*
* RelationPutHeapTuple - place tuple at specified page
@@ -239,8 +241,14 @@ RelationAddExtraBlocks(Relation relation, BulkInsertState bistate)
* Immediately update the bottom level of the FSM. This has a good
* chance of making this page visible to other concurrently inserting
* backends, and we want that to happen without delay.
+ *
+ * Since we know the table will end up with extraBlocks additional
+ * pages, we pass the final number to avoid possible unnecessary
+ * system calls and to make sure the FSM is created when we add
+ * the first new page.
*/
- RecordPageWithFreeSpace(relation, blockNum, freespace);
+ RecordPageWithFreeSpace(relation, blockNum, freespace,
+ blockNum + extraBlocks);
}
while (--extraBlocks > 0);
@@ -378,24 +386,15 @@ RelationGetBufferForTuple(Relation relation, Size len,
* target.
*/
targetBlock = GetPageWithFreeSpace(relation, len + saveFreeSpace);
-
- /*
- * If the FSM knows nothing of the rel, try the last page before we
- * give up and extend. This avoids one-tuple-per-page syndrome during
- * bootstrapping or in a recently-started system.
- */
- if (targetBlock == InvalidBlockNumber)
- {
- BlockNumber nblocks = RelationGetNumberOfBlocks(relation);
-
- if (nblocks > 0)
- targetBlock = nblocks - 1;
- }
}
loop:
while (targetBlock != InvalidBlockNumber)
{
+
+#ifdef TRACE_TARGETBLOCK
+ elog(DEBUG1, "Attempting block %u", targetBlock);
+#endif
/*
* Read and exclusive-lock the target block, as well as the other
* block if one was given, taking suitable care with lock ordering and
@@ -484,6 +483,17 @@ loop:
{
/* use this page as future insert target, too */
RelationSetTargetBlock(relation, targetBlock);
+
+ /*
+ * In case we used an in-memory map of available blocks, reset
+ * it for next use.
+ */
+ if (targetBlock < HEAP_FSM_CREATION_THRESHOLD)
+ ClearLocalMap();
+
+#ifdef TRACE_TARGETBLOCK
+ elog(DEBUG1, "Returning buffer for block %u", targetBlock);
+#endif
return buffer;
}
@@ -557,11 +567,18 @@ loop:
goto loop;
}
+#ifdef TRACE_TARGETBLOCK
+ elog(DEBUG1, "Bulk-extending relation");
+#endif
/* Time to bulk-extend. */
RelationAddExtraBlocks(relation, bistate);
}
}
+#ifdef TRACE_TARGETBLOCK
+ elog(DEBUG1, "Extending relation");
+#endif
+
/*
* In addition to whatever extension we performed above, we always add at
* least one block to satisfy our own request.
@@ -600,10 +617,11 @@ loop:
* risk wiping out valid data).
*/
page = BufferGetPage(buffer);
+ targetBlock = BufferGetBlockNumber(buffer);
if (!PageIsNew(page))
elog(ERROR, "page %u of relation \"%s\" should be empty but is not",
- BufferGetBlockNumber(buffer),
+ targetBlock,
RelationGetRelationName(relation));
PageInit(page, BufferGetPageSize(buffer), 0);
@@ -623,7 +641,18 @@ loop:
* current backend to make more insertions or not, which is probably a
* good bet most of the time. So for now, don't add it to FSM yet.
*/
- RelationSetTargetBlock(relation, BufferGetBlockNumber(buffer));
+ RelationSetTargetBlock(relation, targetBlock);
+
+ /*
+ * In case we used an in-memory map of available blocks, reset
+ * it for next use. We do this unconditionally since after relation
+ * extension we can't reliably skip this based on the targetBlock.
+ */
+ ClearLocalMap();
+
+#ifdef TRACE_TARGETBLOCK
+ elog(DEBUG1, "Returning buffer for block %u", targetBlock);
+#endif
return buffer;
}
diff --git a/src/backend/commands/vacuumlazy.c b/src/backend/commands/vacuumlazy.c
index 8996d366e9..9f4d8adcdb 100644
--- a/src/backend/commands/vacuumlazy.c
+++ b/src/backend/commands/vacuumlazy.c
@@ -154,7 +154,7 @@ static BufferAccessStrategy vac_strategy;
static void lazy_scan_heap(Relation onerel, int options,
LVRelStats *vacrelstats, Relation *Irel, int nindexes,
bool aggressive);
-static void lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats);
+static void lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats, BlockNumber nblocks);
static bool lazy_check_needs_freeze(Buffer buf, bool *hastup);
static void lazy_vacuum_index(Relation indrel,
IndexBulkDeleteResult **stats,
@@ -759,7 +759,7 @@ lazy_scan_heap(Relation onerel, int options, LVRelStats *vacrelstats,
pgstat_progress_update_multi_param(2, hvp_index, hvp_val);
/* Remove tuples from heap */
- lazy_vacuum_heap(onerel, vacrelstats);
+ lazy_vacuum_heap(onerel, vacrelstats, nblocks);
/*
* Forget the now-vacuumed tuples, and press on, but be careful
@@ -897,7 +897,7 @@ lazy_scan_heap(Relation onerel, int options, LVRelStats *vacrelstats,
MarkBufferDirty(buf);
UnlockReleaseBuffer(buf);
- RecordPageWithFreeSpace(onerel, blkno, freespace);
+ RecordPageWithFreeSpace(onerel, blkno, freespace, nblocks);
continue;
}
@@ -936,7 +936,7 @@ lazy_scan_heap(Relation onerel, int options, LVRelStats *vacrelstats,
}
UnlockReleaseBuffer(buf);
- RecordPageWithFreeSpace(onerel, blkno, freespace);
+ RecordPageWithFreeSpace(onerel, blkno, freespace, nblocks);
continue;
}
@@ -1339,7 +1339,7 @@ lazy_scan_heap(Relation onerel, int options, LVRelStats *vacrelstats,
* taken if there are no indexes.)
*/
if (vacrelstats->num_dead_tuples == prev_dead_count)
- RecordPageWithFreeSpace(onerel, blkno, freespace);
+ RecordPageWithFreeSpace(onerel, blkno, freespace, nblocks);
}
/* report that everything is scanned and vacuumed */
@@ -1401,7 +1401,7 @@ lazy_scan_heap(Relation onerel, int options, LVRelStats *vacrelstats,
/* Remove tuples from heap */
pgstat_progress_update_param(PROGRESS_VACUUM_PHASE,
PROGRESS_VACUUM_PHASE_VACUUM_HEAP);
- lazy_vacuum_heap(onerel, vacrelstats);
+ lazy_vacuum_heap(onerel, vacrelstats, nblocks);
vacrelstats->num_index_scans++;
}
@@ -1472,9 +1472,10 @@ lazy_scan_heap(Relation onerel, int options, LVRelStats *vacrelstats,
* Note: the reason for doing this as a second pass is we cannot remove
* the tuples until we've removed their index entries, and we want to
* process index entry removal in batches as large as possible.
+ * Note: nblocks is passed as an optimization for RecordPageWithFreeSpace().
*/
static void
-lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats)
+lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats, BlockNumber nblocks)
{
int tupindex;
int npages;
@@ -1511,7 +1512,7 @@ lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats)
freespace = PageGetHeapFreeSpace(page);
UnlockReleaseBuffer(buf);
- RecordPageWithFreeSpace(onerel, tblk, freespace);
+ RecordPageWithFreeSpace(onerel, tblk, freespace, nblocks);
npages++;
}
diff --git a/src/backend/storage/freespace/README b/src/backend/storage/freespace/README
index e7ff23b76f..abaec871a5 100644
--- a/src/backend/storage/freespace/README
+++ b/src/backend/storage/freespace/README
@@ -5,10 +5,11 @@ Free Space Map
The purpose of the free space map is to quickly locate a page with enough
free space to hold a tuple to be stored; or to determine that no such page
-exists and the relation must be extended by one page. As of PostgreSQL 8.4
-each relation has its own, extensible free space map stored in a separate
-"fork" of its relation. This eliminates the disadvantages of the former
-fixed-size FSM.
+exists and the relation must be extended by one page. For very small heap
+relations, we simply iterate through all the pages in descending order.
+Otherwise, each relation (except for hash indexes) has its own, extensible
+free space map stored in a separate "fork" of its relation. This eliminates
+the disadvantages of the fixed-size FSM used in PostgreSQL 8.3 and earlier.
It is important to keep the map small so that it can be searched rapidly.
Therefore, we don't attempt to record the exact free space on a page.
@@ -192,5 +193,3 @@ TODO
----
- fastroot to avoid traversing upper nodes with just 1 child
-- use a different system for tables that fit into one FSM page, with a
- mechanism to switch to the real thing as it grows.
diff --git a/src/backend/storage/freespace/freespace.c b/src/backend/storage/freespace/freespace.c
index 7c4ad1c449..fd37ca6a5c 100644
--- a/src/backend/storage/freespace/freespace.c
+++ b/src/backend/storage/freespace/freespace.c
@@ -76,6 +76,11 @@
#define FSM_ROOT_LEVEL (FSM_TREE_DEPTH - 1)
#define FSM_BOTTOM_LEVEL 0
+/* Status codes for the local map. */
+#define FSM_LOCAL_ZERO 0x00 /* Beyond the end of the relation */
+#define FSM_LOCAL_AVAIL 0x01 /* Available to try */
+#define FSM_LOCAL_TRIED 0x02 /* Already tried, not enough space */
+
/*
* The internal FSM routines work on a logical addressing scheme. Each
* level of the tree can be thought of as a separately addressable file.
@@ -89,6 +94,9 @@ typedef struct
/* Address of the root page. */
static const FSMAddress FSM_ROOT_ADDRESS = {FSM_ROOT_LEVEL, 0};
+/* Local map of block numbers for small heaps with no FSM. */
+static char FSMLocalMap[HEAP_FSM_CREATION_THRESHOLD] = {FSM_LOCAL_ZERO};
+
/* functions to navigate the tree */
static FSMAddress fsm_get_child(FSMAddress parent, uint16 slot);
static FSMAddress fsm_get_parent(FSMAddress child, uint16 *slot);
@@ -106,11 +114,15 @@ static Size fsm_space_cat_to_avail(uint8 cat);
/* workhorse functions for various operations */
static int fsm_set_and_search(Relation rel, FSMAddress addr, uint16 slot,
- uint8 newValue, uint8 minValue);
+ uint8 newValue, uint8 minValue);
+static void fsm_local_set(Relation rel, BlockNumber nblocks);
static BlockNumber fsm_search(Relation rel, uint8 min_cat);
+static BlockNumber fsm_local_search(void);
static uint8 fsm_vacuum_page(Relation rel, FSMAddress addr,
BlockNumber start, BlockNumber end,
bool *eof);
+static bool fsm_allow_writes(Relation rel, BlockNumber heapblk,
+ BlockNumber nblocks, BlockNumber *get_nblocks);
/******** Public API ********/
@@ -132,8 +144,35 @@ BlockNumber
GetPageWithFreeSpace(Relation rel, Size spaceNeeded)
{
uint8 min_cat = fsm_space_needed_to_cat(spaceNeeded);
+ BlockNumber target_block,
+ nblocks;
+
+ /* First try the FSM, if it exists. */
+ target_block = fsm_search(rel, min_cat);
- return fsm_search(rel, min_cat);
+ if (target_block == InvalidBlockNumber &&
+ rel->rd_rel->relkind == RELKIND_RELATION)
+ {
+ nblocks = RelationGetNumberOfBlocks(rel);
+
+ if (nblocks > HEAP_FSM_CREATION_THRESHOLD)
+ {
+ /*
+ * If the FSM knows nothing of the rel, try the last page before
+ * we give up and extend. This avoids one-tuple-per-page syndrome
+ * during bootstrapping or in a recently-started system.
+ */
+ target_block = nblocks - 1;
+ }
+ else if (nblocks > 0)
+ {
+ /* Create or update local map and get first candidate block. */
+ fsm_local_set(rel, nblocks);
+ target_block = fsm_local_search();
+ }
+ }
+
+ return target_block;
}
/*
@@ -149,11 +188,38 @@ BlockNumber
RecordAndGetPageWithFreeSpace(Relation rel, BlockNumber oldPage,
Size oldSpaceAvail, Size spaceNeeded)
{
- int old_cat = fsm_space_avail_to_cat(oldSpaceAvail);
- int search_cat = fsm_space_needed_to_cat(spaceNeeded);
+ int old_cat;
+ int search_cat;
FSMAddress addr;
uint16 slot;
int search_slot;
+ BlockNumber nblocks = InvalidBlockNumber;
+
+ /* First try the local map, if it exists. */
+ if (oldPage < HEAP_FSM_CREATION_THRESHOLD &&
+ FSMLocalMap[oldPage] == FSM_LOCAL_AVAIL)
+ {
+ Assert(rel->rd_rel->relkind == RELKIND_RELATION);
+
+ FSMLocalMap[oldPage] = FSM_LOCAL_TRIED;
+ return fsm_local_search();
+ }
+
+ if (!fsm_allow_writes(rel, oldPage, InvalidBlockNumber, &nblocks))
+ {
+ /*
+ * If we have neither a local map nor an FSM, we probably just
+ * tried the target block in the smgr relation entry and failed,
+ * so we'll need to create the local map.
+ */
+ fsm_local_set(rel, nblocks);
+ return fsm_local_search();
+ }
+
+ /* Normal FSM logic follows */
+
+ old_cat = fsm_space_avail_to_cat(oldSpaceAvail);
+ search_cat = fsm_space_needed_to_cat(spaceNeeded);
/* Get the location of the FSM byte representing the heap block */
addr = fsm_get_location(oldPage, &slot);
@@ -178,18 +244,35 @@ RecordAndGetPageWithFreeSpace(Relation rel, BlockNumber oldPage,
* FreeSpaceMapVacuum call, which updates the upper level pages.
*/
void
-RecordPageWithFreeSpace(Relation rel, BlockNumber heapBlk, Size spaceAvail)
+RecordPageWithFreeSpace(Relation rel, BlockNumber heapBlk,
+ Size spaceAvail, BlockNumber nblocks)
{
- int new_cat = fsm_space_avail_to_cat(spaceAvail);
+ int new_cat;
FSMAddress addr;
uint16 slot;
+ BlockNumber dummy;
+
+ if (!fsm_allow_writes(rel, heapBlk, nblocks, &dummy))
+ /* Note: We do not have a local map to update, either. */
+ return;
/* Get the location of the FSM byte representing the heap block */
addr = fsm_get_location(heapBlk, &slot);
+ new_cat = fsm_space_avail_to_cat(spaceAvail);
fsm_set_and_search(rel, addr, slot, new_cat, 0);
}
+/*
+ * Clear the local map. We must call this when we have found a block with
+ * enough free space, or when we extend the relation.
+ */
+void
+ClearLocalMap(void)
+{
+ memset(FSMLocalMap, 0, sizeof(FSMLocalMap));
+}
+
/*
* XLogRecordPageWithFreeSpace - like RecordPageWithFreeSpace, for use in
* WAL replay
@@ -204,6 +287,30 @@ XLogRecordPageWithFreeSpace(RelFileNode rnode, BlockNumber heapBlk,
BlockNumber blkno;
Buffer buf;
Page page;
+ bool write_to_fsm;
+
+ /* This is meant to mirror the logic in fsm_allow_writes() */
+ if (heapBlk > HEAP_FSM_CREATION_THRESHOLD)
+ write_to_fsm = true;
+ else
+ {
+ /* Open the relation at smgr level */
+ SMgrRelation smgr = smgropen(rnode, InvalidBackendId);
+
+ if (smgrexists(smgr, FSM_FORKNUM))
+ write_to_fsm = true;
+ else
+ {
+ BlockNumber heap_nblocks = smgrnblocks(smgr, MAIN_FORKNUM);
+ if (heap_nblocks > HEAP_FSM_CREATION_THRESHOLD)
+ write_to_fsm = true;
+ else
+ write_to_fsm = false;
+ }
+ }
+
+ if (!write_to_fsm)
+ return;
/* Get the location of the FSM byte representing the heap block */
addr = fsm_get_location(heapBlk, &slot);
@@ -904,3 +1011,118 @@ fsm_vacuum_page(Relation rel, FSMAddress addr,
return max_avail;
}
+
+/*
+ * For heaps we prevent extension of the FSM unless the number of pages
+ * exceeds HEAP_FSM_CREATION_THRESHOLD. For tables that don't already have
+ * a FSM, this will save an inode and a few kB of space.
+ *
+ * XXX The API is a little awkward -- if the caller has a valid nblocks,
+ * it can pass it as an optimization to avoid a system call. If the caller
+ * passes InvalidBlockNumber and receives a false return value, it can
+ * get an up-to-date relation size from get_nblocks.
+ */
+static bool
+fsm_allow_writes(Relation rel, BlockNumber heapblk,
+ BlockNumber nblocks, BlockNumber *get_nblocks)
+{
+ bool skip_get_nblocks;
+
+ if (heapblk > HEAP_FSM_CREATION_THRESHOLD)
+ return true;
+
+ /* Index rels can always create an FSM. */
+ if (rel->rd_rel->relkind != RELKIND_RELATION)
+ return true;
+
+ /*
+ * If the caller knows nblocks, we can avoid a system call later.
+ * If it doesn't, maybe we have relpages from a previous VACUUM.
+ * Since the table may have extended since then, we still have to
+ * count the pages later if we can't return now.
+ */
+ if (nblocks != InvalidBlockNumber)
+ {
+ if (nblocks > HEAP_FSM_CREATION_THRESHOLD)
+ return true;
+ else
+ skip_get_nblocks = true;
+ }
+ else
+ {
+ if (rel->rd_rel->relpages != InvalidBlockNumber &&
+ rel->rd_rel->relpages > HEAP_FSM_CREATION_THRESHOLD)
+ return true;
+ else
+ skip_get_nblocks = false;
+ }
+
+ RelationOpenSmgr(rel);
+ if (smgrexists(rel->rd_smgr, FSM_FORKNUM))
+ return true;
+
+ if (skip_get_nblocks)
+ return false;
+
+ /* last resort */
+ *get_nblocks = RelationGetNumberOfBlocks(rel);
+ if (*get_nblocks > HEAP_FSM_CREATION_THRESHOLD)
+ return true;
+ else
+ return false;
+}
+
+/*
+ * Set or update the local map of blocks to try, for when there is no FSM.
+ * It's designed specifically to be idempotent, so the heap insert code
+ * should only clear the map when it has found a free block or when it
+ * has to extend the relation. That way, if we have tried all blocks we
+ * know about, but the rel has been extended by another backend, this will
+ * set only newly added blocks to 'available'.
+ */
+static void
+fsm_local_set(Relation rel, BlockNumber nblocks)
+{
+ BlockNumber blkno,
+ cached_target_block;
+
+ /*
+ * If the blkno is beyond the end of the relation, the status should
+ * be zero already, but make sure it is. If the blkno is within the
+ * relation, mark it available unless it's already been tried.
+ */
+ for (blkno = 0; blkno < HEAP_FSM_CREATION_THRESHOLD; blkno++)
+ {
+ if (blkno < nblocks)
+ FSMLocalMap[blkno] |= FSM_LOCAL_AVAIL;
+ else
+ FSMLocalMap[blkno] = FSM_LOCAL_ZERO;
+ }
+
+ /* Set the status of the cached target block to 'tried'. */
+ cached_target_block = RelationGetTargetBlock(rel);
+ if (cached_target_block != InvalidBlockNumber &&
+ cached_target_block < HEAP_FSM_CREATION_THRESHOLD)
+ FSMLocalMap[cached_target_block] = FSM_LOCAL_TRIED;
+}
+
+/*
+ * Search the local map for an available block to try, in descending order.
+ *
+ * For use when there is no FSM.
+ */
+static BlockNumber
+fsm_local_search(void)
+{
+ BlockNumber target_block = HEAP_FSM_CREATION_THRESHOLD;
+
+ do
+ {
+ target_block--;
+ if (FSMLocalMap[target_block] == FSM_LOCAL_AVAIL)
+ return target_block;
+ }
+ while (target_block > 0);
+
+ return InvalidBlockNumber;
+}
diff --git a/src/backend/storage/freespace/indexfsm.c b/src/backend/storage/freespace/indexfsm.c
index e21047b96f..d8fd29a7eb 100644
--- a/src/backend/storage/freespace/indexfsm.c
+++ b/src/backend/storage/freespace/indexfsm.c
@@ -51,7 +51,7 @@ GetFreeIndexPage(Relation rel)
void
RecordFreeIndexPage(Relation rel, BlockNumber freeBlock)
{
- RecordPageWithFreeSpace(rel, freeBlock, BLCKSZ - 1);
+ RecordPageWithFreeSpace(rel, freeBlock, BLCKSZ - 1, InvalidBlockNumber);
}
@@ -61,7 +61,7 @@ RecordFreeIndexPage(Relation rel, BlockNumber freeBlock)
void
RecordUsedIndexPage(Relation rel, BlockNumber usedBlock)
{
- RecordPageWithFreeSpace(rel, usedBlock, 0);
+ RecordPageWithFreeSpace(rel, usedBlock, 0, InvalidBlockNumber);
}
/*
diff --git a/src/include/storage/freespace.h b/src/include/storage/freespace.h
index 726eb30fb8..ab7f552b70 100644
--- a/src/include/storage/freespace.h
+++ b/src/include/storage/freespace.h
@@ -18,6 +18,9 @@
#include "storage/relfilenode.h"
#include "utils/relcache.h"
+/* Only extend a heap's FSM if the heap has greater than this many blocks */
+#define HEAP_FSM_CREATION_THRESHOLD 8
+
/* prototypes for public functions in freespace.c */
extern Size GetRecordedFreeSpace(Relation rel, BlockNumber heapBlk);
extern BlockNumber GetPageWithFreeSpace(Relation rel, Size spaceNeeded);
@@ -26,7 +29,8 @@ extern BlockNumber RecordAndGetPageWithFreeSpace(Relation rel,
Size oldSpaceAvail,
Size spaceNeeded);
extern void RecordPageWithFreeSpace(Relation rel, BlockNumber heapBlk,
- Size spaceAvail);
+ Size spaceAvail, BlockNumber nblocks);
+extern void ClearLocalMap(void);
extern void XLogRecordPageWithFreeSpace(RelFileNode rnode, BlockNumber heapBlk,
Size spaceAvail);
--
2.17.1
From 9b1a35aa768749a7c823df64c761cef60fbb22a7 Mon Sep 17 00:00:00 2001
From: John Naylor <jcnay...@gmail.com>
Date: Wed, 31 Oct 2018 14:28:03 +0700
Subject: [PATCH v7 2/2] During pg_upgrade, skip transfer of FSMs if they
wouldn't have been created on the new cluster.
---
src/bin/pg_upgrade/info.c | 11 +++++--
src/bin/pg_upgrade/pg_upgrade.h | 6 +++-
src/bin/pg_upgrade/relfilenode.c | 55 +++++++++++++++++++-------------
3 files changed, 47 insertions(+), 25 deletions(-)
diff --git a/src/bin/pg_upgrade/info.c b/src/bin/pg_upgrade/info.c
index fd0b44c3ce..31a24e0bec 100644
--- a/src/bin/pg_upgrade/info.c
+++ b/src/bin/pg_upgrade/info.c
@@ -200,6 +200,7 @@ create_rel_filename_map(const char *old_data, const char *new_data,
map->old_db_oid = old_db->db_oid;
map->new_db_oid = new_db->db_oid;
+ map->relkind = old_rel->relkind;
/*
* old_relfilenode might differ from pg_class.oid (and hence
@@ -418,6 +419,7 @@ get_rel_infos(ClusterInfo *cluster, DbInfo *dbinfo)
char *nspname = NULL;
char *relname = NULL;
char *tablespace = NULL;
+ char *relkind = NULL;
int i_spclocation,
i_nspname,
i_relname,
@@ -425,7 +427,8 @@ get_rel_infos(ClusterInfo *cluster, DbInfo *dbinfo)
i_indtable,
i_toastheap,
i_relfilenode,
- i_reltablespace;
+ i_reltablespace,
+ i_relkind;
char query[QUERY_ALLOC];
char *last_namespace = NULL,
*last_tablespace = NULL;
@@ -497,7 +500,7 @@ get_rel_infos(ClusterInfo *cluster, DbInfo *dbinfo)
*/
snprintf(query + strlen(query), sizeof(query) - strlen(query),
"SELECT all_rels.*, n.nspname, c.relname, "
- " c.relfilenode, c.reltablespace, %s "
+ " c.relfilenode, c.reltablespace, c.relkind, %s "
"FROM (SELECT * FROM regular_heap "
" UNION ALL "
" SELECT * FROM toast_heap "
@@ -529,6 +532,7 @@ get_rel_infos(ClusterInfo *cluster, DbInfo *dbinfo)
i_relfilenode = PQfnumber(res, "relfilenode");
i_reltablespace = PQfnumber(res, "reltablespace");
i_spclocation = PQfnumber(res, "spclocation");
+ i_relkind = PQfnumber(res, "relkind");
for (relnum = 0; relnum < ntups; relnum++)
{
@@ -558,6 +562,9 @@ get_rel_infos(ClusterInfo *cluster, DbInfo *dbinfo)
relname = PQgetvalue(res, relnum, i_relname);
curr->relname = pg_strdup(relname);
+ relkind = PQgetvalue(res, relnum, i_relkind);
+ curr->relkind = relkind[0];
+
curr->relfilenode = atooid(PQgetvalue(res, relnum, i_relfilenode));
curr->tblsp_alloc = false;
diff --git a/src/bin/pg_upgrade/pg_upgrade.h b/src/bin/pg_upgrade/pg_upgrade.h
index f83a3eeb67..78df636a2a 100644
--- a/src/bin/pg_upgrade/pg_upgrade.h
+++ b/src/bin/pg_upgrade/pg_upgrade.h
@@ -147,6 +147,7 @@ typedef struct
char *tablespace; /* tablespace path; "" for cluster default */
bool nsp_alloc; /* should nspname be freed? */
bool tblsp_alloc; /* should tablespace be freed? */
+ char relkind; /* relation relkind -- see pg_class.h */
} RelInfo;
typedef struct
@@ -173,9 +174,12 @@ typedef struct
*/
Oid old_relfilenode;
Oid new_relfilenode;
- /* the rest are used only for logging and error reporting */
+
+ /* These are used only for logging and error reporting. */
char *nspname; /* namespaces */
char *relname;
+
+ char relkind; /* relation relkind -- see pg_class.h */
} FileNameMap;
/*
diff --git a/src/bin/pg_upgrade/relfilenode.c b/src/bin/pg_upgrade/relfilenode.c
index ed604f26ca..7a7f6ab244 100644
--- a/src/bin/pg_upgrade/relfilenode.c
+++ b/src/bin/pg_upgrade/relfilenode.c
@@ -14,10 +14,11 @@
#include <sys/stat.h>
#include "catalog/pg_class_d.h"
#include "access/transam.h"
+#include "storage/freespace.h"
static void transfer_single_new_db(FileNameMap *maps, int size, char *old_tablespace);
-static void transfer_relfile(FileNameMap *map, const char *suffix, bool vm_must_add_frozenbit);
+static Size transfer_relfile(FileNameMap *map, const char *suffix, bool vm_must_add_frozenbit);
/*
@@ -136,6 +137,7 @@ transfer_single_new_db(FileNameMap *maps, int size, char *old_tablespace)
int mapnum;
bool vm_crashsafe_match = true;
bool vm_must_add_frozenbit = false;
+ Size first_seg_size = 0;
/*
* Do the old and new cluster disagree on the crash-safetiness of the vm
@@ -157,18 +159,22 @@ transfer_single_new_db(FileNameMap *maps, int size, char *old_tablespace)
if (old_tablespace == NULL ||
strcmp(maps[mapnum].old_tablespace, old_tablespace) == 0)
{
- /* transfer primary file */
- transfer_relfile(&maps[mapnum], "", vm_must_add_frozenbit);
+ /* Transfer main fork and return size of the first segment. */
+ first_seg_size = transfer_relfile(&maps[mapnum], "", vm_must_add_frozenbit);
/* fsm/vm files added in PG 8.4 */
if (GET_MAJOR_VERSION(old_cluster.major_version) >= 804)
{
/*
- * Copy/link any fsm and vm files, if they exist
+ * Copy/link any fsm and vm files, if they exist and if they would
+ * be created in the new cluster.
*/
- transfer_relfile(&maps[mapnum], "_fsm", vm_must_add_frozenbit);
+ if (maps[mapnum].relkind != RELKIND_RELATION ||
+ first_seg_size > HEAP_FSM_CREATION_THRESHOLD * BLCKSZ ||
+ GET_MAJOR_VERSION(new_cluster.major_version) <= 1100)
+ (void) transfer_relfile(&maps[mapnum], "_fsm", vm_must_add_frozenbit);
if (vm_crashsafe_match)
- transfer_relfile(&maps[mapnum], "_vm", vm_must_add_frozenbit);
+ (void) transfer_relfile(&maps[mapnum], "_vm", vm_must_add_frozenbit);
}
}
}
@@ -182,7 +188,7 @@ transfer_single_new_db(FileNameMap *maps, int size, char *old_tablespace)
* is true, visibility map forks are converted and rewritten, even in link
* mode.
*/
-static void
+static Size
transfer_relfile(FileNameMap *map, const char *type_suffix, bool vm_must_add_frozenbit)
{
char old_file[MAXPGPATH];
@@ -190,6 +196,8 @@ transfer_relfile(FileNameMap *map, const char *type_suffix, bool vm_must_add_fro
int segno;
char extent_suffix[65];
struct stat statbuf;
+ int sret;
+ Size first_seg_size = 0;
/*
* Now copy/link any related segments as well. Remember, PG breaks large
@@ -218,26 +226,29 @@ transfer_relfile(FileNameMap *map, const char *type_suffix, bool vm_must_add_fro
type_suffix,
extent_suffix);
- /* Is it an extent, fsm, or vm file? */
- if (type_suffix[0] != '\0' || segno != 0)
- {
- /* Did file open fail? */
- if (stat(old_file, &statbuf) != 0)
- {
- /* File does not exist? That's OK, just return */
- if (errno == ENOENT)
- return;
- else
- pg_fatal("error while checking for file existence \"%s.%s\" (\"%s\" to \"%s\"): %s\n",
- map->nspname, map->relname, old_file, new_file,
- strerror(errno));
- }
+ sret = stat(old_file, &statbuf);
+ /* Save the size of the first segment of the main fork. */
+ if (type_suffix[0] == '\0' && segno == 0)
+ first_seg_size = statbuf.st_size;
+
+ /* The file must be an extent, fsm, or vm. */
+ else if (sret == 0)
+ {
/* If file is empty, just return */
if (statbuf.st_size == 0)
- return;
+ return first_seg_size;
}
+ /* Did file open fail? */
+ else if (errno == ENOENT)
+ /* File does not exist? That's OK, just return */
+ return first_seg_size;
+ else
+ pg_fatal("error while checking for file existence \"%s.%s\" (\"%s\" to \"%s\"): %s\n",
+ map->nspname, map->relname, old_file, new_file,
+ strerror(errno));
+
unlink(new_file);
/* Copying files might take some time, so give feedback. */
--
2.17.1
setup-fsm-pg_upgrade.sql
Description: application/sql
