From: shess <shess@noemail.net>
Date: Tue, 29 Jul 2008 01:13:02 +0000 (+0000)
Subject: Re-used prepared statement from fts3 cursor.  Previously, each call to
X-Git-Tag: version-3.6.10~688
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b5f94870c24c3a4c9e83adadcb38d42691b4d9d8;p=thirdparty%2Fsqlite.git

Re-used prepared statement from fts3 cursor.  Previously, each call to
fulltextFilter() finalized any existing prepared statement and
prepared a new one.  In the case where idxNum has not changed, simply
reseting the statement suffices.  This provides an order of magnitude
speedup in incoming joins against docid. (CVS 5489)

FossilOrigin-Name: a08a5f2b1256b8a93beca5a359ccfc28d403efa3
---

diff --git a/ext/fts3/fts3.c b/ext/fts3/fts3.c
index f9f8c4aa31..cc6dcd82d2 100644
--- a/ext/fts3/fts3.c
+++ b/ext/fts3/fts3.c
@@ -4102,21 +4102,43 @@ static int fulltextFilter(
   fulltext_cursor *c = (fulltext_cursor *) pCursor;
   fulltext_vtab *v = cursor_vtab(c);
   int rc;
-  StringBuffer sb;
 
   FTSTRACE(("FTS3 Filter %p\n",pCursor));
 
-  initStringBuffer(&sb);
-  append(&sb, "SELECT docid, ");
-  appendList(&sb, v->nColumn, v->azContentColumn);
-  append(&sb, " FROM %_content");
-  if( idxNum!=QUERY_GENERIC ) append(&sb, " WHERE docid = ?");
-  sqlite3_finalize(c->pStmt);
-  rc = sql_prepare(v->db, v->zDb, v->zName, &c->pStmt, stringBufferData(&sb));
-  stringBufferDestroy(&sb);
-  if( rc!=SQLITE_OK ) return rc;
+  /* If the cursor has a statement that was not prepared according to
+  ** idxNum, clear it.  I believe all calls to fulltextFilter with a
+  ** given cursor will have the same idxNum , but in this case it's
+  ** easy to be safe.
+  */
+  if( c->pStmt && c->iCursorType!=idxNum ){
+    sqlite3_finalize(c->pStmt);
+    c->pStmt = NULL;
+  }
+
+  /* Get a fresh statement appropriate to idxNum. */
+  /* TODO(shess): Add a prepared-statement cache in the vt structure.
+  ** The cache must handle multiple open cursors.  Easier to cache the
+  ** statement variants at the vt to reduce malloc/realloc/free here.
+  ** Or we could have a StringBuffer variant which allowed stack
+  ** construction for small values.
+  */
+  if( !c->pStmt ){
+    StringBuffer sb;
+    initStringBuffer(&sb);
+    append(&sb, "SELECT docid, ");
+    appendList(&sb, v->nColumn, v->azContentColumn);
+    append(&sb, " FROM %_content");
+    if( idxNum!=QUERY_GENERIC ) append(&sb, " WHERE docid = ?");
+    rc = sql_prepare(v->db, v->zDb, v->zName, &c->pStmt,
+                     stringBufferData(&sb));
+    stringBufferDestroy(&sb);
+    if( rc!=SQLITE_OK ) return rc;
+    c->iCursorType = idxNum;
+  }else{
+    sqlite3_reset(c->pStmt);
+    assert( c->iCursorType==idxNum );
+  }
 
-  c->iCursorType = idxNum;
   switch( idxNum ){
     case QUERY_GENERIC:
       break;
diff --git a/manifest b/manifest
index 22da79fbfc..db8d84e71d 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Implement\sthe\s"lookaside"\smemory\sallocation\scache.\s\sUse\sof\sthis\scache\smakes\nthe\sspeed1.test\sscript\srun\sabout\s15%\sfaster.\s\sAdded\snew\sinterfaces\sto\ncontrol\sthe\scache.\s(CVS\s5488)
-D 2008-07-28T19:34:53
+C Re-used\sprepared\sstatement\sfrom\sfts3\scursor.\s\sPreviously,\seach\scall\sto\nfulltextFilter()\sfinalized\sany\sexisting\sprepared\sstatement\sand\nprepared\sa\snew\sone.\s\sIn\sthe\scase\swhere\sidxNum\shas\snot\schanged,\ssimply\nreseting\sthe\sstatement\ssuffices.\s\sThis\sprovides\san\sorder\sof\smagnitude\nspeedup\sin\sincoming\sjoins\sagainst\sdocid.\s(CVS\s5489)
+D 2008-07-29T01:13:02
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in bbb62eecc851379aef5a48a1bf8787eb13e6ec06
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -51,7 +51,7 @@ F ext/fts2/fts2_tokenizer1.c 8545ce12b41922004da46e91a7b023b92b76f94e
 F ext/fts2/mkfts2amal.tcl 974d5d438cb3f7c4a652639262f82418c1e4cff0
 F ext/fts3/README.tokenizers 226644a0eab97724e8de83061912e8bb248461b6
 F ext/fts3/README.txt 8c18f41574404623b76917b9da66fcb0ab38328d
-F ext/fts3/fts3.c 14ac2e37889fda1555d903648772b6be3061d2bb
+F ext/fts3/fts3.c fa37048c369491ba6fb74e1732f24a8a8daaef65
 F ext/fts3/fts3.h 3a10a0af180d502cecc50df77b1b22df142817fe
 F ext/fts3/fts3_hash.c 83e7bb4042106b32811681dd2859b4577a7a6b35
 F ext/fts3/fts3_hash.h 004b759e1602ff16dfa02fea3ca1c77336ad6798
@@ -612,7 +612,7 @@ F tool/speedtest16.c c8a9c793df96db7e4933f0852abb7a03d48f2e81
 F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 1dbced29de5f59ba2ebf877edcadf171540374d1
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
-P 51be2e4463ca32f290feb610f59553b55bc67a5c
-R 1624ec122f5ffb86a37761ed2b47d75a
-U drh
-Z 5a311db47e066a208f5f741cb81e1882
+P e48f9697e9fea339e150ddc32940760027dd07d9
+R 680fb3be123f951c8c77ef4a340cd813
+U shess
+Z b0abfd8b0f9f50c33d751a3bf926e781
diff --git a/manifest.uuid b/manifest.uuid
index 5aad7c290a..ffd7b409b3 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-e48f9697e9fea339e150ddc32940760027dd07d9
\ No newline at end of file
+a08a5f2b1256b8a93beca5a359ccfc28d403efa3
\ No newline at end of file