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Commita063baa

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Remove UpdateFreeSpaceMap(), use FreeSpaceMapVacuumRange() instead.
FreeSpaceMapVacuumRange has the same effect, is more efficient if manypages are involved, and makes fewer assumptions about how it's used.Notably, Claudio Freire pointed out that UpdateFreeSpaceMap could failif the specified freespace value isn't the maximum possible. This isn'ta problem for the single existing user, but the function represents anattractive nuisance IMO, because it's named as though it were ageneral-purpose update function and its limitations are undocumented.In any case we don't need multiple ways to get the same result.In passing, do some code review and cleanup in RelationAddExtraBlocks.In particular, I see no excuse for it to omit the PageIsNew safety checkthat's done in the mainline extension path in RelationGetBufferForTuple.Discussion:https://postgr.es/m/CAGTBQpYR0uJCNTt3M5GOzBRHo+-GccNO1nCaQ8yEJmZKSW5q1A@mail.gmail.com
1 parentbc0021e commita063baa

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3 files changed

+30
-99
lines changed

3 files changed

+30
-99
lines changed

‎src/backend/access/heap/hio.c

Lines changed: 30 additions & 14 deletions
Original file line numberDiff line numberDiff line change
@@ -177,13 +177,10 @@ GetVisibilityMapPins(Relation relation, Buffer buffer1, Buffer buffer2,
177177
staticvoid
178178
RelationAddExtraBlocks(Relationrelation,BulkInsertStatebistate)
179179
{
180-
Pagepage;
181-
BlockNumberblockNum=InvalidBlockNumber,
180+
BlockNumberblockNum,
182181
firstBlock=InvalidBlockNumber;
183-
intextraBlocks=0;
184-
intlockWaiters=0;
185-
Sizefreespace=0;
186-
Bufferbuffer;
182+
intextraBlocks;
183+
intlockWaiters;
187184

188185
/* Use the length of the lock wait queue to judge how much to extend. */
189186
lockWaiters=RelationExtensionLockWaiterCount(relation);
@@ -198,18 +195,40 @@ RelationAddExtraBlocks(Relation relation, BulkInsertState bistate)
198195
*/
199196
extraBlocks=Min(512,lockWaiters*20);
200197

201-
while (extraBlocks-- >=0)
198+
do
202199
{
203-
/* Ouch - an unnecessary lseek() each time through the loop! */
200+
Bufferbuffer;
201+
Pagepage;
202+
Sizefreespace;
203+
204+
/*
205+
* Extend by one page. This should generally match the main-line
206+
* extension code in RelationGetBufferForTuple, except that we hold
207+
* the relation extension lock throughout.
208+
*/
204209
buffer=ReadBufferBI(relation,P_NEW,bistate);
205210

206-
/* Extend by one page. */
207211
LockBuffer(buffer,BUFFER_LOCK_EXCLUSIVE);
208212
page=BufferGetPage(buffer);
213+
214+
if (!PageIsNew(page))
215+
elog(ERROR,"page %u of relation \"%s\" should be empty but is not",
216+
BufferGetBlockNumber(buffer),
217+
RelationGetRelationName(relation));
218+
209219
PageInit(page,BufferGetPageSize(buffer),0);
220+
221+
/*
222+
* We mark all the new buffers dirty, but do nothing to write them
223+
* out; they'll probably get used soon, and even if they are not, a
224+
* crash will leave an okay all-zeroes page on disk.
225+
*/
210226
MarkBufferDirty(buffer);
227+
228+
/* we'll need this info below */
211229
blockNum=BufferGetBlockNumber(buffer);
212230
freespace=PageGetHeapFreeSpace(page);
231+
213232
UnlockReleaseBuffer(buffer);
214233

215234
/* Remember first block number thus added. */
@@ -223,18 +242,15 @@ RelationAddExtraBlocks(Relation relation, BulkInsertState bistate)
223242
*/
224243
RecordPageWithFreeSpace(relation,blockNum,freespace);
225244
}
245+
while (--extraBlocks>0);
226246

227247
/*
228248
* Updating the upper levels of the free space map is too expensive to do
229249
* for every block, but it's worth doing once at the end to make sure that
230250
* subsequent insertion activity sees all of those nifty free pages we
231251
* just inserted.
232-
*
233-
* Note that we're using the freespace value that was reported for the
234-
* last block we added as if it were the freespace value for every block
235-
* we added. That's actually true, because they're all equally empty.
236252
*/
237-
UpdateFreeSpaceMap(relation,firstBlock,blockNum,freespace);
253+
FreeSpaceMapVacuumRange(relation,firstBlock,blockNum+1);
238254
}
239255

240256
/*

‎src/backend/storage/freespace/freespace.c

Lines changed: 0 additions & 81 deletions
Original file line numberDiff line numberDiff line change
@@ -111,8 +111,6 @@ static BlockNumber fsm_search(Relation rel, uint8 min_cat);
111111
staticuint8fsm_vacuum_page(Relationrel,FSMAddressaddr,
112112
BlockNumberstart,BlockNumberend,
113113
bool*eof);
114-
staticBlockNumberfsm_get_lastblckno(Relationrel,FSMAddressaddr);
115-
staticvoidfsm_update_recursive(Relationrel,FSMAddressaddr,uint8new_cat);
116114

117115

118116
/******** Public API ********/
@@ -192,46 +190,6 @@ RecordPageWithFreeSpace(Relation rel, BlockNumber heapBlk, Size spaceAvail)
192190
fsm_set_and_search(rel,addr,slot,new_cat,0);
193191
}
194192

195-
/*
196-
* Update the upper levels of the free space map all the way up to the root
197-
* to make sure we don't lose track of new blocks we just inserted. This is
198-
* intended to be used after adding many new blocks to the relation; we judge
199-
* it not worth updating the upper levels of the tree every time data for
200-
* a single page changes, but for a bulk-extend it's worth it.
201-
*/
202-
void
203-
UpdateFreeSpaceMap(Relationrel,BlockNumberstartBlkNum,
204-
BlockNumberendBlkNum,Sizefreespace)
205-
{
206-
intnew_cat=fsm_space_avail_to_cat(freespace);
207-
FSMAddressaddr;
208-
uint16slot;
209-
BlockNumberblockNum;
210-
BlockNumberlastBlkOnPage;
211-
212-
blockNum=startBlkNum;
213-
214-
while (blockNum <=endBlkNum)
215-
{
216-
/*
217-
* Find FSM address for this block; update tree all the way to the
218-
* root.
219-
*/
220-
addr=fsm_get_location(blockNum,&slot);
221-
fsm_update_recursive(rel,addr,new_cat);
222-
223-
/*
224-
* Get the last block number on this FSM page. If that's greater than
225-
* or equal to our endBlkNum, we're done. Otherwise, advance to the
226-
* first block on the next page.
227-
*/
228-
lastBlkOnPage=fsm_get_lastblckno(rel,addr);
229-
if (lastBlkOnPage >=endBlkNum)
230-
break;
231-
blockNum=lastBlkOnPage+1;
232-
}
233-
}
234-
235193
/*
236194
* XLogRecordPageWithFreeSpace - like RecordPageWithFreeSpace, for use in
237195
*WAL replay
@@ -929,42 +887,3 @@ fsm_vacuum_page(Relation rel, FSMAddress addr,
929887

930888
returnmax_avail;
931889
}
932-
933-
/*
934-
* This function will return the last block number stored on given
935-
* FSM page address.
936-
*/
937-
staticBlockNumber
938-
fsm_get_lastblckno(Relationrel,FSMAddressaddr)
939-
{
940-
intslot;
941-
942-
/*
943-
* Get the last slot number on the given address and convert that to block
944-
* number
945-
*/
946-
slot=SlotsPerFSMPage-1;
947-
returnfsm_get_heap_blk(addr,slot);
948-
}
949-
950-
/*
951-
* Recursively update the FSM tree from given address to
952-
* all the way up to root.
953-
*/
954-
staticvoid
955-
fsm_update_recursive(Relationrel,FSMAddressaddr,uint8new_cat)
956-
{
957-
uint16parentslot;
958-
FSMAddressparent;
959-
960-
if (addr.level==FSM_ROOT_LEVEL)
961-
return;
962-
963-
/*
964-
* Get the parent page and our slot in the parent page, and update the
965-
* information in that.
966-
*/
967-
parent=fsm_get_parent(addr,&parentslot);
968-
fsm_set_and_search(rel,parent,parentslot,new_cat,0);
969-
fsm_update_recursive(rel,parent,new_cat);
970-
}

‎src/include/storage/freespace.h

Lines changed: 0 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -34,9 +34,5 @@ extern void FreeSpaceMapTruncateRel(Relation rel, BlockNumber nblocks);
3434
externvoidFreeSpaceMapVacuum(Relationrel);
3535
externvoidFreeSpaceMapVacuumRange(Relationrel,BlockNumberstart,
3636
BlockNumberend);
37-
externvoidUpdateFreeSpaceMap(Relationrel,
38-
BlockNumberstartBlkNum,
39-
BlockNumberendBlkNum,
40-
Sizefreespace);
4137

4238
#endif/* FREESPACE_H_ */

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