Add the btree_sample(INDEX,LOCATION,LIMIT) pragma.

FossilOrigin-Name: affc2ef5ee3d8885e74051fd508a3d6f8c313857

diff --git a/manifest b/manifest
index ab3ba2497d7d00bc5fc12f51e99148b1a2e493fe..539805fc1c774126510d3158e7b63cddedcac4d8 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sproblems\sin\sthe\sest_count\spragma\sfor\sindexes\sand\sWITHOUT\sROWID\stables.
-D 2016-10-21T15:36:51.551
+C Add\sthe\sbtree_sample(INDEX,LOCATION,LIMIT)\spragma.
+D 2016-10-21T17:25:47.070
 F Makefile.in 6fd48ffcf7c2deea7499062d1f3747f986c19678
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 5151cc64c4c05f3455f4f692ad11410a810d937f
@@ -329,7 +329,7 @@ F src/auth.c 930b376a9c56998557367e6f7f8aaeac82a2a792
 F src/backup.c faf17e60b43233c214aae6a8179d24503a61e83b
 F src/bitvec.c 3ee4c8b2c94ed3a7377256e18199e6ff5cf33f63
 F src/btmutex.c bc87dd3b062cc26edfe79918de2200ccb8d41e73
-F src/btree.c c58b8a52ad8a74d48835a0471fadec0851d113fb
+F src/btree.c 955375bb1537dc16d9b59ad6fcfe31c5a140d1e3
 F src/btree.h 012576c1d0000e96ccc785c6fe22b4be8211f0d9
 F src/btreeInt.h c18b7d2a3494695133e4e60ee36061d37f45d9a5
 F src/build.c e22e66fb34e1e50bb7869a510923bfe58db3071a
@@ -379,8 +379,8 @@ F src/parse.y 07f68096c97093793ed04d69db8bb75e55c3e00e
 F src/pcache.c 5ff2a08f76a9c1b22f43eb063b7068fb085465ac
 F src/pcache.h 2cedcd8407eb23017d92790b112186886e179490
 F src/pcache1.c e3967219b2a92b9edcb9324a4ba75009090d3953
-F src/pragma.c e33c2c772e838402ff940eed581992a693a4a91a
-F src/pragma.h 30d6559672c6755be452ea5fdf2e9bf32acc69a3
+F src/pragma.c 3ef6e3168ed02ebc8247b3fc0d612b6fc6b0db24
+F src/pragma.h 74d46e32bdc7abb2d01710162ff96cfb483699b6
 F src/prepare.c b1140c3d0cf59bc85ace00ce363153041b424b7a
 F src/printf.c a5f0ca08ddede803c241266abb46356ec748ded1
 F src/random.c ba2679f80ec82c4190062d756f22d0c358180696
@@ -453,7 +453,7 @@ F src/update.c 8179e699dbd45b92934fd02d3d8e3732e8da8802
 F src/utf.c 699001c79f28e48e9bcdf8a463da029ea660540c
 F src/util.c 3e2da6101888d073e79ecc6af5e0a2f70fa1e498
 F src/vacuum.c 913970b9d86dd6c2b8063ef1af421880f1464ec3
-F src/vdbe.c c07f9a771c82619be14cc5368b19623ed8f3a30d
+F src/vdbe.c 55ea5eb95860106a8f665231f8d0c6b55dbf8974
 F src/vdbe.h c044be7050ac6bf596eecc6ab159f5dbc020a3b7
 F src/vdbeInt.h 0a18713d0a2fec6807d076bd333d9bf3e57530cd
 F src/vdbeapi.c 8272f9342c39ab8d7eb4b9decc6caa7bc75b7d83
@@ -1464,7 +1464,7 @@ F tool/mkmsvcmin.tcl 2f12f7fa8858bbe61cf81820a2da96c79ed1ca8d
 F tool/mkopcodec.tcl d1b6362bd3aa80d5520d4d6f3765badf01f6c43c
 F tool/mkopcodeh.tcl a01d2c1d8a6205b03fc635adf3735b4c523befd3
 F tool/mkopts.tcl 66ac10d240cc6e86abd37dc908d50382f84ff46e
-F tool/mkpragmatab.tcl bf6417cc44d42c1d024ac7036b59b9a8d4476470
+F tool/mkpragmatab.tcl c5ce5c56a8193196efcd195f09572a073445397f
 F tool/mkspeedsql.tcl a1a334d288f7adfe6e996f2e712becf076745c97
 F tool/mksqlite3c-noext.tcl fef88397668ae83166735c41af99d79f56afaabb
 F tool/mksqlite3c.tcl 06b2e6a0f21cc0a5d70fbbd136b3e0a96470645e
@@ -1526,7 +1526,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 340822afbe0c6b47fdd789c56acd9e1058a434cb
-R e90ad2ebf1bcb25a55e3e2678b19c035
+P c39fd9b8f11b3f1df489df1df4197fe4a670732c
+R 6376d702c2a44655952c143d8109c737
 U drh
-Z 01c14e3ae29abee9ef7e5b8de3cc1480
+Z a6dc86cd66f951dc83fd16ce4ecf3406

diff --git a/manifest.uuid b/manifest.uuid
index b65dc96bc325b65e532c934da5f9b8c942b55eb0..87232ebeea6aa81f877e8b74c27983d109b38da9 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-c39fd9b8f11b3f1df489df1df4197fe4a670732c
\ No newline at end of file
+affc2ef5ee3d8885e74051fd508a3d6f8c313857
\ No newline at end of file

diff --git a/src/btree.c b/src/btree.c
index 696e1be98cf40b048be0934cec2573b2bbbe7259..07c7eadaaddc84fabe0609267a330b2e72559036 100644 (file)
--- a/src/btree.c
+++ b/src/btree.c
@@ -5095,8 +5095,10 @@ int sqlite3BtreeMovetoProportional(
   }else{
     perChild = mx/pPage->nCell;
     rx = x/perChild;
+    if( rx>=pPage->nCell ) rx = pPage->nCell-1;
   }
   pCur->aiIdx[pCur->iPage] = rx;
+
   return SQLITE_OK;
 }
 

diff --git a/src/pragma.c b/src/pragma.c
index b2eedbcf0a8c0c21d8ac773370c0eb5a293274bf..c512d3ba8d8a203b2cf929a3b38710e152bd0093 100644 (file)
--- a/src/pragma.c
+++ b/src/pragma.c
@@ -1430,6 +1430,84 @@ void sqlite3Pragma(
   }
   break;
 
+  /*
+  **   PRAGMA btree_sample(<table-or-index>,<fraction>,<limit>);
+  **
+  ** Seek in <table-or-index> through the first <fraction> of rows and
+  ** then begin returning rows, one by one.  A max of <limit> rows will
+  ** be returned.
+  */
+  case PragTyp_BTREE_SAMPLE: {
+    Index *pIdx;
+    Table *pTab = 0;
+    Pgno iRoot = 0;
+    int nCol = 0;
+    const char *zName = 0;
+    int iLimit = 10;
+    int i;
+    int regResult;
+    int regLimit;
+    int addrTop;
+    int addrJmp;
+    int addrSkip;
+    double r;
+    if( (pIdx = sqlite3FindIndex(db, zRight, zDb))!=0 ){
+      iRoot = pIdx->tnum;
+      zName = pIdx->zName;
+      nCol = pIdx->nColumn;
+    }else if( (pTab = sqlite3FindTable(db, zRight, zDb))!=0 ){
+      zName = pTab->zName;
+      if( HasRowid(pTab) ){
+        iRoot = pTab->tnum;
+        nCol = pTab->nCol;
+      }else{
+        pIdx = sqlite3PrimaryKeyIndex(pTab);
+        iRoot = pIdx->tnum;
+        nCol = pIdx->nColumn;
+      }
+    }else{
+      break;
+    }
+    sqlite3VdbeSetNumCols(v, nCol);
+    for(i=0; i<nCol; i++){
+      char zCol[30];
+      sqlite3_snprintf(sizeof(zCol),zCol,"c%06d",i);
+      sqlite3VdbeSetColName(v, i, COLNAME_NAME, zCol, SQLITE_TRANSIENT);
+    }
+    if( pValues->nId>=2 ){
+      const char *z = pValues->a[1].zName;
+      sqlite3AtoF(z, &r, sqlite3Strlen30(z), SQLITE_UTF8);
+    }else{
+      r = 0.5;
+    }
+    if( r<0.0 ) r = 0.0;
+    if( r>1.0 ) r = 1.0;
+    if( pValues->nId>=3 ){
+      iLimit = sqlite3Atoi(pValues->a[2].zName);
+    }
+    pParse->nTab++;
+    sqlite3TableLock(pParse, iDb, iRoot, 0, zName);
+    sqlite3CodeVerifySchema(pParse, iDb);
+    sqlite3VdbeAddOp4Int(v, OP_OpenRead, 0, iRoot, iDb, nCol);
+    if( pIdx ) sqlite3VdbeSetP4KeyInfo(pParse, pIdx);
+    regLimit = ++pParse->nMem;
+    regResult = pParse->nMem+1;
+    pParse->nMem += nCol;
+    sqlite3VdbeAddOp2(v, OP_Integer, iLimit, regLimit);
+    addrSkip = sqlite3VdbeAddOp1(v, OP_Rewind, 0); VdbeCoverage(v);
+    sqlite3VdbeAddOp3(v, OP_EstRowCnt, 0, regResult, (int)(r*1000000000));
+    addrTop = sqlite3VdbeCurrentAddr(v);
+    for(i=0; i<nCol; i++){
+      sqlite3VdbeAddOp3(v, OP_Column, 0, i, regResult+i);
+    }
+    sqlite3VdbeAddOp2(v, OP_ResultRow, regResult, nCol);
+    addrJmp = sqlite3VdbeAddOp1(v, OP_DecrJumpZero, regLimit); VdbeCoverage(v);
+    sqlite3VdbeAddOp2(v, OP_Next, 0, addrTop); VdbeCoverage(v);
+    sqlite3VdbeJumpHere(v, addrJmp);
+    sqlite3VdbeJumpHere(v, addrSkip);
+  }
+  break;
+
 #ifndef SQLITE_INTEGRITY_CHECK_ERROR_MAX
 # define SQLITE_INTEGRITY_CHECK_ERROR_MAX 100
 #endif

diff --git a/src/pragma.h b/src/pragma.h
index 182addc70f61a202ea2e95fd08f728816bb7da69..ab70897f55ae81ab91f9a5fd680866e1da2b572b 100644 (file)
--- a/src/pragma.h
+++ b/src/pragma.h
@@ -6,47 +6,48 @@
 #define PragTyp_HEADER_VALUE                   0
 #define PragTyp_AUTO_VACUUM                    1
 #define PragTyp_FLAG                           2
-#define PragTyp_BUSY_TIMEOUT                   3
-#define PragTyp_CACHE_SIZE                     4
-#define PragTyp_CACHE_SPILL                    5
-#define PragTyp_CASE_SENSITIVE_LIKE            6
-#define PragTyp_COLLATION_LIST                 7
-#define PragTyp_COMPILE_OPTIONS                8
-#define PragTyp_DATA_STORE_DIRECTORY           9
-#define PragTyp_DATABASE_LIST                 10
-#define PragTyp_DEFAULT_CACHE_SIZE            11
-#define PragTyp_ENCODING                      12
-#define PragTyp_EST_COUNT                     13
-#define PragTyp_FOREIGN_KEY_CHECK             14
-#define PragTyp_FOREIGN_KEY_LIST              15
-#define PragTyp_INCREMENTAL_VACUUM            16
-#define PragTyp_INDEX_INFO                    17
-#define PragTyp_INDEX_LIST                    18
-#define PragTyp_INTEGRITY_CHECK               19
-#define PragTyp_JOURNAL_MODE                  20
-#define PragTyp_JOURNAL_SIZE_LIMIT            21
-#define PragTyp_LOCK_PROXY_FILE               22
-#define PragTyp_LOCKING_MODE                  23
-#define PragTyp_PAGE_COUNT                    24
-#define PragTyp_MMAP_SIZE                     25
-#define PragTyp_PAGE_SIZE                     26
-#define PragTyp_SECURE_DELETE                 27
-#define PragTyp_SHRINK_MEMORY                 28
-#define PragTyp_SOFT_HEAP_LIMIT               29
-#define PragTyp_STATS                         30
-#define PragTyp_SYNCHRONOUS                   31
-#define PragTyp_TABLE_INFO                    32
-#define PragTyp_TEMP_STORE                    33
-#define PragTyp_TEMP_STORE_DIRECTORY          34
-#define PragTyp_THREADS                       35
-#define PragTyp_WAL_AUTOCHECKPOINT            36
-#define PragTyp_WAL_CHECKPOINT                37
-#define PragTyp_ACTIVATE_EXTENSIONS           38
-#define PragTyp_HEXKEY                        39
-#define PragTyp_KEY                           40
-#define PragTyp_REKEY                         41
-#define PragTyp_LOCK_STATUS                   42
-#define PragTyp_PARSER_TRACE                  43
+#define PragTyp_BTREE_SAMPLE                   3
+#define PragTyp_BUSY_TIMEOUT                   4
+#define PragTyp_CACHE_SIZE                     5
+#define PragTyp_CACHE_SPILL                    6
+#define PragTyp_CASE_SENSITIVE_LIKE            7
+#define PragTyp_COLLATION_LIST                 8
+#define PragTyp_COMPILE_OPTIONS                9
+#define PragTyp_DATA_STORE_DIRECTORY          10
+#define PragTyp_DATABASE_LIST                 11
+#define PragTyp_DEFAULT_CACHE_SIZE            12
+#define PragTyp_ENCODING                      13
+#define PragTyp_EST_COUNT                     14
+#define PragTyp_FOREIGN_KEY_CHECK             15
+#define PragTyp_FOREIGN_KEY_LIST              16
+#define PragTyp_INCREMENTAL_VACUUM            17
+#define PragTyp_INDEX_INFO                    18
+#define PragTyp_INDEX_LIST                    19
+#define PragTyp_INTEGRITY_CHECK               20
+#define PragTyp_JOURNAL_MODE                  21
+#define PragTyp_JOURNAL_SIZE_LIMIT            22
+#define PragTyp_LOCK_PROXY_FILE               23
+#define PragTyp_LOCKING_MODE                  24
+#define PragTyp_PAGE_COUNT                    25
+#define PragTyp_MMAP_SIZE                     26
+#define PragTyp_PAGE_SIZE                     27
+#define PragTyp_SECURE_DELETE                 28
+#define PragTyp_SHRINK_MEMORY                 29
+#define PragTyp_SOFT_HEAP_LIMIT               30
+#define PragTyp_STATS                         31
+#define PragTyp_SYNCHRONOUS                   32
+#define PragTyp_TABLE_INFO                    33
+#define PragTyp_TEMP_STORE                    34
+#define PragTyp_TEMP_STORE_DIRECTORY          35
+#define PragTyp_THREADS                       36
+#define PragTyp_WAL_AUTOCHECKPOINT            37
+#define PragTyp_WAL_CHECKPOINT                38
+#define PragTyp_ACTIVATE_EXTENSIONS           39
+#define PragTyp_HEXKEY                        40
+#define PragTyp_KEY                           41
+#define PragTyp_REKEY                         42
+#define PragTyp_LOCK_STATUS                   43
+#define PragTyp_PARSER_TRACE                  44
 #define PragFlag_NeedSchema           0x01
 #define PragFlag_ReadOnly             0x02
 static const struct sPragmaNames {
@@ -81,6 +82,10 @@ static const struct sPragmaNames {
     /* iArg:      */ SQLITE_AutoIndex },
 #endif
 #endif
+  { /* zName:     */ "btree_sample",
+    /* ePragTyp:  */ PragTyp_BTREE_SAMPLE,
+    /* ePragFlag: */ PragFlag_NeedSchema,
+    /* iArg:      */ 0 },
   { /* zName:     */ "busy_timeout",
     /* ePragTyp:  */ PragTyp_BUSY_TIMEOUT,
     /* ePragFlag: */ 0,
@@ -466,4 +471,4 @@ static const struct sPragmaNames {
     /* iArg:      */ SQLITE_WriteSchema|SQLITE_RecoveryMode },
 #endif
 };
-/* Number of pragmas: 61 on by default, 74 total. */
+/* Number of pragmas: 62 on by default, 75 total. */

diff --git a/src/vdbe.c b/src/vdbe.c
index 40db24d0e4f4ed38a423d7e6a38397828f0bdfb8..b8e1a9d3033abb0faf1911b7f5b5bf52df39106e 100644 (file)
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -4919,6 +4919,9 @@ case OP_EstRowCnt: {  /* out2 */
   pOut = out2Prerelease(p, pOp);
   pOut->flags = MEM_Real;
   pOut->u.r = n;
+  pC->nullRow = 0;
+  pC->deferredMoveto = 0;
+  pC->cacheStatus = CACHE_STALE;
   break;
 }
 

diff --git a/tool/mkpragmatab.tcl b/tool/mkpragmatab.tcl
index cc2c3e263067127b1074b32e1890be4c238cce32..cac776d668ceb7127059eda15438569fbb6fa0fc 100644 (file)
--- a/tool/mkpragmatab.tcl
+++ b/tool/mkpragmatab.tcl
@@ -254,6 +254,9 @@ set pragma_def {
   NAME: est_count
   FLAG: NeedSchema
 
+  NAME: btree_sample
+  FLAG: NeedSchema
+
   NAME: encoding
   IF:   !defined(SQLITE_OMIT_UTF16)