SQLite

        sqlite3VdbeAddOp2(v, OP_Integer, 0, 7);
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
          sqlite3VdbeAddOp2(v, OP_Integer, 0, 8+j); /* index entries counter */
        }
        pParse->nMem = MAX(pParse->nMem, 8+j);
        sqlite3VdbeAddOp2(v, OP_Rewind, iDataCur, 0); VdbeCoverage(v);
        loopTop = sqlite3VdbeAddOp2(v, OP_AddImm, 7, 1);
        /* Verify that all NOT NULL columns really are NOT NULL */
        for(j=0; j<pTab->nCol; j++){
          char *zErr;
          int jmp2, jmp3;
          if( j==pTab->iPKey ) continue;
          if( pTab->aCol[j].notNull==0 ) continue;
          sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, j, 3);
          sqlite3VdbeChangeP5(v, OPFLAG_TYPEOFARG);
          jmp2 = sqlite3VdbeAddOp1(v, OP_NotNull, 3); VdbeCoverage(v);
          sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1); /* Decrement error limit */
          zErr = sqlite3MPrintf(db, "NULL value in %s.%s", pTab->zName,
                              pTab->aCol[j].zName);
          sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, zErr, P4_DYNAMIC);
          sqlite3VdbeAddOp2(v, OP_ResultRow, 3, 1);
          jmp3 = sqlite3VdbeAddOp1(v, OP_IfPos, 1); VdbeCoverage(v);
          sqlite3VdbeAddOp0(v, OP_Halt);
          sqlite3VdbeJumpHere(v, jmp2);
          sqlite3VdbeJumpHere(v, jmp3);
        }
        /* Validate index entries for the current row */
        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
          int jmp2, jmp3, jmp4, jmp5;
          int ckUniq = sqlite3VdbeMakeLabel(v);
          if( pPk==pIdx ) continue;
          r1 = sqlite3GenerateIndexKey(pParse, pIdx, iDataCur, 0, 0, &jmp3,
                                       pPrior, r1);
          pPrior = pIdx;
          sqlite3VdbeAddOp2(v, OP_AddImm, 8+j, 1);  /* increment entry count */
          /* Verify that an index entry exists for the current table row */
          jmp2 = sqlite3VdbeAddOp4Int(v, OP_Found, iIdxCur+j, ckUniq, r1,
                                      pIdx->nColumn); VdbeCoverage(v);
          sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1); /* Decrement error limit */
          sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, "row ", P4_STATIC);
          sqlite3VdbeAddOp3(v, OP_Concat, 7, 3, 3);
          sqlite3VdbeAddOp4(v, OP_String8, 0, 4, 0, 
                            " missing from index ", P4_STATIC);
          sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 3);
          jmp5 = sqlite3VdbeAddOp4(v, OP_String8, 0, 4, 0,
                                   pIdx->zName, P4_TRANSIENT);
          sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 3);
          sqlite3VdbeAddOp2(v, OP_ResultRow, 3, 1);
          jmp4 = sqlite3VdbeAddOp1(v, OP_IfPos, 1); VdbeCoverage(v);
          sqlite3VdbeAddOp0(v, OP_Halt);
          sqlite3VdbeJumpHere(v, jmp2);
          /* For UNIQUE indexes, verify that only one entry exists with the
          ** current key.  The entry is unique if (1) any column is NULL
          ** or (2) the next entry has a different key */
          if( IsUniqueIndex(pIdx) ){
            int uniqOk = sqlite3VdbeMakeLabel(v);
            int jmp6;
            int kk;
            for(kk=0; kk<pIdx->nKeyCol; kk++){
              int iCol = pIdx->aiColumn[kk];
              assert( iCol>=0 && iCol<pTab->nCol );
              if( pTab->aCol[iCol].notNull ) continue;
              sqlite3VdbeAddOp2(v, OP_IsNull, r1+kk, uniqOk);
              VdbeCoverage(v);
            }
            jmp6 = sqlite3VdbeAddOp1(v, OP_Next, iIdxCur+j); VdbeCoverage(v);
            sqlite3VdbeAddOp2(v, OP_Goto, 0, uniqOk);
            sqlite3VdbeJumpHere(v, jmp6);
            sqlite3VdbeAddOp4Int(v, OP_IdxGT, iIdxCur+j, uniqOk, r1,
                                 pIdx->nKeyCol); VdbeCoverage(v);
            sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1); /* Decrement error limit */
            sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
                              "non-unique entry in index ", P4_STATIC);
            sqlite3VdbeAddOp2(v, OP_Goto, 0, jmp5);
            sqlite3VdbeResolveLabel(v, uniqOk);
          }
          sqlite3VdbeJumpHere(v, jmp4);
          sqlite3ResolvePartIdxLabel(pParse, jmp3);
        }
        sqlite3VdbeAddOp2(v, OP_Next, iDataCur, loopTop); VdbeCoverage(v);
        sqlite3VdbeJumpHere(v, loopTop-1);
#ifndef SQLITE_OMIT_BTREECOUNT
        sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, 
                     "wrong # of entries in index ", P4_STATIC);

** P4>0 then register P3 is the first of P4 registers that form an unpacked
** record.
**
** Cursor P1 is on an index btree.  If the record identified by P3 and P4
** is a prefix of any entry in P1 then a jump is made to P2 and
** P1 is left pointing at the matching entry.
**
** This operation leaves the cursor in a state where it can be
** advanced in the forward direction.  The Next instruction will work,
** but not the Prev instruction.
**
** See also: NotFound, NoConflict, NotExists. SeekGe
*/
/* Opcode: NotFound P1 P2 P3 P4 *
** Synopsis: key=r[P3@P4]
**
** If P4==0 then register P3 holds a blob constructed by MakeRecord.  If

#endif

  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  assert( pOp->p4type==P4_INT32 );
  pC = p->apCsr[pOp->p1];
  assert( pC!=0 );
#ifdef SQLITE_DEBUG
  pC->seekOp = pOp->opcode;
#endif
  pIn3 = &aMem[pOp->p3];
  assert( pC->pCursor!=0 );
  assert( pC->isTable==0 );
  pFree = 0;  /* Not needed.  Only used to suppress a compiler warning. */
  if( pOp->p4.i>0 ){
    r.pKeyInfo = pC->pKeyInfo;

  assert( pOp->opcode!=OP_NextIfOpen || pOp->p4.xAdvance==sqlite3BtreeNext );
  assert( pOp->opcode!=OP_PrevIfOpen || pOp->p4.xAdvance==sqlite3BtreePrevious);

  /* The Next opcode is only used after SeekGT, SeekGE, and Rewind.
  ** The Prev opcode is only used after SeekLT, SeekLE, and Last. */
  assert( pOp->opcode!=OP_Next || pOp->opcode!=OP_NextIfOpen
       || pC->seekOp==OP_SeekGT || pC->seekOp==OP_SeekGE
       || pC->seekOp==OP_Rewind || pC->seekOp==OP_Found);
  assert( pOp->opcode!=OP_Prev || pOp->opcode!=OP_PrevIfOpen
       || pC->seekOp==OP_SeekLT || pC->seekOp==OP_SeekLE
       || pC->seekOp==OP_Last );

  rc = pOp->p4.xAdvance(pC->pCursor, &res);
next_tail:
  pC->cacheStatus = CACHE_STALE;

  do_test pragma-3.19 {
    catch {db close}
    forcedelete test.db test.db-journal
    sqlite3 db test.db
    db eval {PRAGMA integrity_check}
  } {ok}
}

# Verify that PRAGMA integrity_check catches UNIQUE and NOT NULL
# constraint violations.
#
do_execsql_test pragma-3.20 {
  CREATE TABLE t1(a,b);
  CREATE INDEX t1a ON t1(a);
  INSERT INTO t1 VALUES(1,1),(2,2),(3,3),(2,4),(NULL,5),(NULL,6);
  PRAGMA writable_schema=ON;
  UPDATE sqlite_master SET sql='CREATE UNIQUE INDEX t1a ON t1(a)'
   WHERE name='t1a';
  UPDATE sqlite_master SET sql='CREATE TABLE t1(a NOT NULL,b)'
   WHERE name='t1';
  PRAGMA writable_schema=OFF;
  ALTER TABLE t1 RENAME TO t1x;
  PRAGMA integrity_check;
} {{non-unique entry in index t1a} {NULL value in t1x.a} {non-unique entry in index t1a} {NULL value in t1x.a}}
do_execsql_test pragma-3.21 {
  PRAGMA integrity_check(3);
} {{non-unique entry in index t1a} {NULL value in t1x.a} {non-unique entry in index t1a}}
do_execsql_test pragma-3.22 {
  PRAGMA integrity_check(2);
} {{non-unique entry in index t1a} {NULL value in t1x.a}}
do_execsql_test pragma-3.21 {
  PRAGMA integrity_check(1);
} {{non-unique entry in index t1a}}

# Test modifying the cache_size of an attached database.
ifcapable pager_pragmas&&attach {
do_test pragma-4.1 {
  execsql {
    ATTACH 'test2.db' AS aux;
    pragma aux.cache_size;