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Commit of a *MAJOR* patch from Dan McGuirk <djm@indirect.com>

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Changes:

        * Unique index capability works using the syntax 'create unique
          index'.

        * Duplicate OID's in the system tables are removed.  I put
          little scripts called 'duplicate_oids' and 'find_oid' in
          include/catalog that help to find and remove duplicate OID's.
          I also moved 'unused_oids' from backend/catalog to
          include/catalog, since it has to be in the same directory
          as the include files in order to work.

        * The backend tries converting the name of a function or aggregate
          to all lowercase if the original name given doesn't work (mostly
          for compatibility with ODBC).

        * You can 'SELECT NULL' to your heart's content.

        * I put my _bt_updateitem fix in instead, which uses
          _bt_insertonpg so that even if the new key is so big that
          the page has to be split, everything still works.

        * All literal references to system catalog OID's have been
          replaced with references to define'd constants from the catalog
          header files.

        * I added a couple of node copy functions.  I think this was a
          preliminary attempt to get rules to work.
This commit is contained in:
Marc G. Fournier
1996-11-13 20:56:15 +00:00
parent 0cec8fe26c
commit 07a65b2255
45 changed files with 861 additions and 588 deletions
Download Patch File Download Diff File Expand all files Collapse all files

147
src/backend/access/nbtree/nbtinsert.c
View File

@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.6 1996/11/05 10:35:29 scrappy Exp $
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.7 1996/11/13 20:47:11 scrappy Exp $
*
*-------------------------------------------------------------------------
*/
@@ -31,7 +31,10 @@ static OffsetNumber _bt_findsplitloc(Relation rel, Page page, OffsetNumber start
static void _bt_newroot(Relation rel, Buffer lbuf, Buffer rbuf);
static OffsetNumber _bt_pgaddtup(Relation rel, Buffer buf, int keysz, ScanKey itup_scankey, Size itemsize, BTItem btitem, BTItem afteritem);
static bool _bt_goesonpg(Relation rel, Buffer buf, Size keysz, ScanKey scankey, BTItem afteritem);
#if 0
static void _bt_updateitem(Relation rel, Size keysz, Buffer buf, Oid bti_oid, BTItem newItem);
#endif
/*
* _bt_doinsert() -- Handle insertion of a single btitem in the tree.
@@ -41,7 +44,7 @@ static void _bt_updateitem(Relation rel, Size keysz, Buffer buf, Oid bti_oid, BT
* (xid, seqno) pair.
*/
InsertIndexResult
_bt_doinsert(Relation rel, BTItem btitem)
_bt_doinsert(Relation rel, BTItem btitem, bool index_is_unique, bool is_update)
{
ScanKey itup_scankey;
IndexTuple itup;
@@ -59,6 +62,31 @@ _bt_doinsert(Relation rel, BTItem btitem)
/* find the page containing this key */
stack = _bt_search(rel, natts, itup_scankey, &buf);
/* if we're not allowing duplicates, make sure the key isn't */
/* already in the node */
if(index_is_unique && !is_update) {
OffsetNumber offset;
TupleDesc itupdesc;
Page page;
itupdesc = RelationGetTupleDescriptor(rel);
page = BufferGetPage(buf);
offset = _bt_binsrch(rel, buf, natts, itup_scankey, BT_DESCENT);
/* make sure the offset we're given points to an actual */
/* key on the page before trying to compare it */
if(!PageIsEmpty(page) &&
offset <= PageGetMaxOffsetNumber(page)) {
if(!_bt_compare(rel, itupdesc, page,
natts, itup_scankey, offset)) {
/* it is a duplicate */
elog(WARN, "Cannot insert a duplicate key into a unique index.");
}
}
}
blkno = BufferGetBlockNumber(buf);
/* trade in our read lock for a write lock */
@@ -137,6 +165,10 @@ _bt_insertonpg(Relation rel,
InsertIndexResult newres;
BTItem new_item = (BTItem) NULL;
BTItem lowLeftItem;
OffsetNumber leftmost_offset;
Page ppage;
BTPageOpaque ppageop;
BlockNumber bknum;
page = BufferGetPage(buf);
itemsz = IndexTupleDSize(btitem->bti_itup)
@@ -236,14 +268,67 @@ _bt_insertonpg(Relation rel,
lowLeftItem =
(BTItem) PageGetItem(page,
PageGetItemId(page, P_FIRSTKEY));
/* page must have right pointer after split */
_bt_updateitem(rel, keysz, pbuf, stack->bts_btitem->bti_oid,
lowLeftItem);
/* this method does not work--_bt_updateitem tries to */
/* overwrite an entry with another entry that might be */
/* bigger. if lowLeftItem is bigger, it corrupts the */
/* parent page. instead, we have to delete the original */
/* leftmost item from the parent, and insert the new one */
/* with a regular _bt_insertonpg (it could cause a split */
/* because it's bigger than what was there before). */
/* --djm 8/21/96 */
/* _bt_updateitem(rel, keysz, pbuf, stack->bts_btitem->bti_oid,
lowLeftItem); */
/* get the parent page */
ppage = BufferGetPage(pbuf);
ppageop = (BTPageOpaque) PageGetSpecialPointer(ppage);
/* figure out which key is leftmost (if the parent page */
/* is rightmost, too, it must be the root) */
if(P_RIGHTMOST(ppageop)) {
leftmost_offset = P_HIKEY;
} else {
leftmost_offset = P_FIRSTKEY;
}
PageIndexTupleDelete(ppage, leftmost_offset);
/* don't write anything out yet--we still have the write */
/* lock, and now we call another _bt_insertonpg to */
/* insert the correct leftmost key */
/* make a new leftmost item, using the tuple data from */
/* lowLeftItem. point it to the left child. */
/* update it on the stack at the same time. */
bknum = BufferGetBlockNumber(buf);
pfree(stack->bts_btitem);
stack->bts_btitem = _bt_formitem(&(lowLeftItem->bti_itup));
ItemPointerSet(&(stack->bts_btitem->bti_itup.t_tid),
bknum, P_HIKEY);
/* unlock the children before doing this */
_bt_relbuf(rel, buf, BT_WRITE);
_bt_relbuf(rel, rbuf, BT_WRITE);
/* a regular _bt_binsrch should find the right place to */
/* put the new entry, since it should be lower than any */
/* other key on the page, therefore set afteritem to NULL */
newskey = _bt_mkscankey(rel, &(stack->bts_btitem->bti_itup));
newres = _bt_insertonpg(rel, pbuf, stack->bts_parent,
keysz, newskey, stack->bts_btitem,
NULL);
pfree(newres);
pfree(newskey);
/* don't need the children anymore */
/* we have now lost our lock on the parent buffer, and */
/* need to get it back. */
pbuf = _bt_getstackbuf(rel, stack, BT_WRITE);
} else {
_bt_relbuf(rel, buf, BT_WRITE);
_bt_relbuf(rel, rbuf, BT_WRITE);
}
newskey = _bt_mkscankey(rel, &(new_item->bti_itup));
newres = _bt_insertonpg(rel, pbuf, stack->bts_parent,
@@ -787,6 +872,8 @@ _bt_itemcmp(Relation rel,
return (true);
}
#if 0
/* gone since updating in place doesn't work in general --djm 11/13/96 */
/*
* _bt_updateitem() -- updates the key of the item identified by the
* oid with the key of newItem (done in place if
@@ -804,9 +891,9 @@ _bt_updateitem(Relation rel,
OffsetNumber maxoff;
OffsetNumber i;
ItemPointerData itemPtrData;
BTItem item, itemCopy;
BTItem item;
IndexTuple oldIndexTuple, newIndexTuple;
int newSize, oldSize, first;
int first;
page = BufferGetPage(buf);
maxoff = PageGetMaxOffsetNumber(page);
@@ -825,48 +912,18 @@ _bt_updateitem(Relation rel,
elog(FATAL, "_bt_getstackbuf was lying!!");
}
if(IndexTupleDSize(newItem->bti_itup) >
IndexTupleDSize(item->bti_itup)) {
elog(NOTICE, "trying to overwrite a smaller value with a bigger one in _bt_updateitem");
elog(WARN, "this is not good.");
}
oldIndexTuple = &(item->bti_itup);
newIndexTuple = &(newItem->bti_itup);
oldSize = DOUBLEALIGN(IndexTupleSize(oldIndexTuple));
newSize = DOUBLEALIGN(IndexTupleSize(newIndexTuple));
#ifdef NBTINSERT_PATCH_DEBUG
printf("_bt_updateitem: newSize=%d, oldSize=%d\n", newSize, oldSize);
#endif
/*
* If new and old item have the same size do the update in place
* and return.
*/
if (oldSize == newSize) {
/* keep the original item pointer */
ItemPointerCopy(&(oldIndexTuple->t_tid), &itemPtrData);
CopyIndexTuple(newIndexTuple, &oldIndexTuple);
ItemPointerCopy(&itemPtrData, &(oldIndexTuple->t_tid));
return;
}
/*
* If new and old items have different size the update in place
* is not possible. In this case the old item is deleted and the
* new one is inserted.
* The new insertion should be done using _bt_insertonpg which
* would also takes care of the page splitting if needed, but
* unfortunately it doesn't work, so PageAddItem is used instead.
* There is the possibility that there is not enough space in the
* page and the item is not inserted.
*/
itemCopy = palloc(newSize);
memmove((char *) itemCopy, (char *) newItem, newSize);
itemCopy->bti_oid = item->bti_oid;
newIndexTuple = &(itemCopy->bti_itup);
ItemPointerCopy(&(oldIndexTuple->t_tid), &(newIndexTuple->t_tid));
/*
* Get the offset number of the item then delete it and insert
* the new item in the same place.
*/
i = OffsetNumberPrev(i);
PageIndexTupleDelete(page, i);
PageAddItem(page, (Item) itemCopy, newSize, i, LP_USED);
pfree(itemCopy);
}
#endif