Add the SQLITE_ENABLE_EARLY_CURSOR_CLOSE compile-time option which causes

read cursors to be closed after their usefulness ends during a two-pass
UPDATE.

FossilOrigin-Name: 7def6c8edd85f19ee09038e01541f75b1f71ca39b9fb782b8f0fcac89207c353

diff --git a/manifest b/manifest
index e366fd4b515dc748d1527038bd542d6df919bc56..2e4ba441558a68fefb877c960fb3ce842330317a 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sa\sbuffer\soverwrite\sthat\scould\soccur\swhen\srunning\san\sfts5\sprefix\squery\nagainst\sa\scorrupt\sdatabase.
-D 2019-01-17T19:11:10.179
+C Add\sthe\sSQLITE_ENABLE_EARLY_CURSOR_CLOSE\scompile-time\soption\swhich\scauses\nread\scursors\sto\sbe\sclosed\safter\stheir\susefulness\sends\sduring\sa\stwo-pass\nUPDATE.
+D 2019-01-17T19:33:16.502
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in 2a9d0331ab57c68173a4c2fe9046fe89c4d916a888e04dd7a2d36958c2bff777
@@ -598,7 +598,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c 3f4f653daf234fe713edbcbca3fec2350417d159d28801feabc702a22c4e213f
 F src/wal.h 606292549f5a7be50b6227bd685fa76e3a4affad71bb8ac5ce4cb5c79f6a176a
 F src/walker.c fb94aadc9099ff9c6506d0a8b88d51266005bcaa265403f3d7caf732a562eb66
-F src/where.c dc293ea4230adf9a323fb2e5750eff565347567a3cd6538f7d0fa93b11c2baae
+F src/where.c c5d201699d03be61c35bc04b96e481b1c8dc68177617ca1db156ef7409da2fae
 F src/whereInt.h 5f14db426ca46a83eabab1ae9aa6d4b8f27504ad35b64c290916289b1ddb2e88
 F src/wherecode.c 89d2ec668aec884dfa7ac500c6744e42ec0590fcd72fb740a8b48326a8412811
 F src/whereexpr.c 36b47f7261d6b6f1a72d774c113b74beddf6745aba1018e64b196e29db233442
@@ -1800,7 +1800,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 49956395e14b61f6bf839e59ae7dd95eb32ebf32f3d16388844de6621b9c2d98
-R ccdd711ece291779868bf4b998109e13
-U dan
-Z 3e6c4473b6a0336dbaa6dadc398f3df8
+P 3910b5639d5c96d1840d4feeea64d3a55073531b7365a4e75d9cda6f119f3cfc
+R b6dbc6b0d1ca56280f7f7c766f04179b
+U drh
+Z bba3575bd34040149ab6eabc06009268

diff --git a/manifest.uuid b/manifest.uuid
index a197c3e10b26d4e7e76e7378edb691f9d596d9fa..8cd49ad797b96c340b3bae0f3250882c0616864b 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-3910b5639d5c96d1840d4feeea64d3a55073531b7365a4e75d9cda6f119f3cfc
\ No newline at end of file
+7def6c8edd85f19ee09038e01541f75b1f71ca39b9fb782b8f0fcac89207c353
\ No newline at end of file

diff --git a/src/where.c b/src/where.c
index bb9787fcee5b18cca27f88006106ecc836c20a19..8be95bcd29849a97d045d0d56bb7043e2b9c1f68 100644 (file)
--- a/src/where.c
+++ b/src/where.c
@@ -5262,6 +5262,29 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
       continue;
     }
 
+#ifdef SQLITE_ENABLE_EARLY_CURSOR_CLOSE
+    /* Close all of the cursors that were opened by sqlite3WhereBegin.
+    ** Except, do not close cursors that will be reused by the OR optimization
+    ** (WHERE_OR_SUBCLAUSE).  And do not close the OP_OpenWrite cursors
+    ** created for the ONEPASS optimization.
+    */
+    if( (pTab->tabFlags & TF_Ephemeral)==0
+     && pTab->pSelect==0
+     && (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)==0
+    ){
+      int ws = pLoop->wsFlags;
+      if( pWInfo->eOnePass==ONEPASS_OFF && (ws & WHERE_IDX_ONLY)==0 ){
+        sqlite3VdbeAddOp1(v, OP_Close, pTabItem->iCursor);
+      }
+      if( (ws & WHERE_INDEXED)!=0
+       && (ws & (WHERE_IPK|WHERE_AUTO_INDEX))==0 
+       && pLevel->iIdxCur!=pWInfo->aiCurOnePass[1]
+      ){
+        sqlite3VdbeAddOp1(v, OP_Close, pLevel->iIdxCur);
+      }
+    }
+#endif
+
     /* If this scan uses an index, make VDBE code substitutions to read data
     ** from the index instead of from the table where possible.  In some cases
     ** this optimization prevents the table from ever being read, which can