SQLite

    int r2 = sqlite3GetTempReg(pParse);
    int addr1;
    sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, r1, BTREE_FILE_FORMAT);
    sqlite3VdbeUsesBtree(v, iDb);
    sqlite3VdbeAddOp2(v, OP_Integer, minFormat, r2);
    addr1 = sqlite3VdbeAddOp3(v, OP_Ge, r2, 0, r1);
    sqlite3VdbeChangeP5(v, SQLITE_NOTNULL); VdbeCoverage(v);
    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, r2);
    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, minFormat);
    sqlite3VdbeJumpHere(v, addr1);
    sqlite3ReleaseTempReg(pParse, r1);
    sqlite3ReleaseTempReg(pParse, r2);
  }
}

/*

    reg2 = pParse->regRoot = ++pParse->nMem;
    reg3 = ++pParse->nMem;
    sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, reg3, BTREE_FILE_FORMAT);
    sqlite3VdbeUsesBtree(v, iDb);
    addr1 = sqlite3VdbeAddOp1(v, OP_If, reg3); VdbeCoverage(v);
    fileFormat = (db->flags & SQLITE_LegacyFileFmt)!=0 ?
                  1 : SQLITE_MAX_FILE_FORMAT;
    sqlite3VdbeAddOp2(v, OP_Integer, fileFormat, reg3);
    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, reg3);
    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, fileFormat);
    sqlite3VdbeAddOp2(v, OP_Integer, ENC(db), reg3);
    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_TEXT_ENCODING, reg3);
    sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_TEXT_ENCODING, ENC(db));
    sqlite3VdbeJumpHere(v, addr1);

    /* This just creates a place-holder record in the sqlite_master table.
    ** The record created does not contain anything yet.  It will be replaced
    ** by the real entry in code generated at sqlite3EndTable().
    **
    ** The rowid for the new entry is left in register pParse->regRowid.

** This plan is not completely bullet-proof.  It is possible for
** the schema to change multiple times and for the cookie to be
** set back to prior value.  But schema changes are infrequent
** and the probability of hitting the same cookie value is only
** 1 chance in 2^32.  So we're safe enough.
*/
void sqlite3ChangeCookie(Parse *pParse, int iDb){
  int r1 = sqlite3GetTempReg(pParse);
  sqlite3 *db = pParse->db;
  Vdbe *v = pParse->pVdbe;
  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
  sqlite3VdbeAddOp2(v, OP_Integer, db->aDb[iDb].pSchema->schema_cookie+1, r1);
  sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_SCHEMA_VERSION, r1);
  sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_SCHEMA_VERSION, 
  sqlite3ReleaseTempReg(pParse, r1);
                    db->aDb[iDb].pSchema->schema_cookie+1);
}

/*
** Measure the number of characters needed to output the given
** identifier.  The number returned includes any quotes used
** but does not include the null terminator.
**

      if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
      aOp[0].p1 = iDb;
      aOp[1].p1 = iDb;
      aOp[6].p1 = SQLITE_DEFAULT_CACHE_SIZE;
    }else{
      int size = sqlite3AbsInt32(sqlite3Atoi(zRight));
      sqlite3BeginWriteOperation(pParse, 0, iDb);
      sqlite3VdbeAddOp2(v, OP_Integer, size, 1);
      sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_DEFAULT_CACHE_SIZE, 1);
      sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_DEFAULT_CACHE_SIZE, size);
      assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
      pDb->pSchema->cache_size = size;
      sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size);
    }
    break;
  }
#endif /* !SQLITE_OMIT_PAGER_PRAGMAS && !SQLITE_OMIT_DEPRECATED */

        */
        static const int iLn = VDBE_OFFSET_LINENO(2);
        static const VdbeOpList setMeta6[] = {
          { OP_Transaction,    0,         1,                 0},    /* 0 */
          { OP_ReadCookie,     0,         1,         BTREE_LARGEST_ROOT_PAGE},
          { OP_If,             1,         0,                 0},    /* 2 */
          { OP_Halt,           SQLITE_OK, OE_Abort,          0},    /* 3 */
          { OP_Integer,        0,         1,                 0},    /* 4 */
          { OP_SetCookie,      0,         BTREE_INCR_VACUUM, 1},    /* 5 */
          { OP_SetCookie,      0,         BTREE_INCR_VACUUM, 0},    /* 4 */
        };
        VdbeOp *aOp;
        int iAddr = sqlite3VdbeCurrentAddr(v);
        sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(setMeta6));
        aOp = sqlite3VdbeAddOpList(v, ArraySize(setMeta6), setMeta6, iLn);
        if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
        aOp[0].p1 = iDb;
        aOp[1].p1 = iDb;
        aOp[2].p2 = iAddr+4;
        aOp[4].p1 = eAuto - 1;
        aOp[5].p1 = iDb;
        aOp[4].p1 = iDb;
        aOp[4].p3 = eAuto - 1;
        sqlite3VdbeUsesBtree(v, iDb);
      }
    }
    break;
  }
#endif

  case PragTyp_HEADER_VALUE: {
    int iCookie = pPragma->iArg;  /* Which cookie to read or write */
    sqlite3VdbeUsesBtree(v, iDb);
    if( zRight && (pPragma->mPragFlag & PragFlag_ReadOnly)==0 ){
      /* Write the specified cookie value */
      static const VdbeOpList setCookie[] = {
        { OP_Transaction,    0,  1,  0},    /* 0 */
        { OP_Integer,        0,  1,  0},    /* 1 */
        { OP_SetCookie,      0,  0,  1},    /* 2 */
        { OP_SetCookie,      0,  0,  0},    /* 1 */
      };
      VdbeOp *aOp;
      sqlite3VdbeVerifyNoMallocRequired(v, ArraySize(setCookie));
      aOp = sqlite3VdbeAddOpList(v, ArraySize(setCookie), setCookie, 0);
      if( ONLY_IF_REALLOC_STRESS(aOp==0) ) break;
      aOp[0].p1 = iDb;
      aOp[1].p1 = sqlite3Atoi(zRight);
      aOp[1].p1 = iDb;
      aOp[2].p1 = iDb;
      aOp[2].p2 = iCookie;
      aOp[1].p2 = iCookie;
      aOp[1].p3 = sqlite3Atoi(zRight);
    }else{
      /* Read the specified cookie value */
      static const VdbeOpList readCookie[] = {
        { OP_Transaction,     0,  0,  0},    /* 0 */
        { OP_ReadCookie,      0,  1,  0},    /* 1 */
        { OP_ResultRow,       1,  1,  0}
      };

  pOut = out2Prerelease(p, pOp);
  pOut->u.i = iMeta;
  break;
}

/* Opcode: SetCookie P1 P2 P3 * *
**
** Write the content of register P3 (interpreted as an integer)
** into cookie number P2 of database P1.  P2==1 is the schema version.  
** P2==2 is the database format. P2==3 is the recommended pager cache 
** Write the integer value P3 into cookie number P2 of database P1.
** P2==1 is the schema version.  P2==2 is the database format.
** P2==3 is the recommended pager cache 
** size, and so forth.  P1==0 is the main database file and P1==1 is the 
** database file used to store temporary tables.
**
** A transaction must be started before executing this opcode.
*/
case OP_SetCookie: {       /* in3 */
case OP_SetCookie: {
  Db *pDb;
  assert( pOp->p2<SQLITE_N_BTREE_META );
  assert( pOp->p1>=0 && pOp->p1<db->nDb );
  assert( DbMaskTest(p->btreeMask, pOp->p1) );
  assert( p->readOnly==0 );
  pDb = &db->aDb[pOp->p1];
  assert( pDb->pBt!=0 );
  assert( sqlite3SchemaMutexHeld(db, pOp->p1, 0) );
  pIn3 = &aMem[pOp->p3];
  sqlite3VdbeMemIntegerify(pIn3);
  /* See note about index shifting on OP_ReadCookie */
  rc = sqlite3BtreeUpdateMeta(pDb->pBt, pOp->p2, (int)pIn3->u.i);
  rc = sqlite3BtreeUpdateMeta(pDb->pBt, pOp->p2, pOp->p3);
  if( pOp->p2==BTREE_SCHEMA_VERSION ){
    /* When the schema cookie changes, record the new cookie internally */
    pDb->pSchema->schema_cookie = (int)pIn3->u.i;
    pDb->pSchema->schema_cookie = pOp->p3;
    db->flags |= SQLITE_InternChanges;
  }else if( pOp->p2==BTREE_FILE_FORMAT ){
    /* Record changes in the file format */
    pDb->pSchema->file_format = (u8)pIn3->u.i;
    pDb->pSchema->file_format = pOp->p3;
  }
  if( pOp->p1==1 ){
    /* Invalidate all prepared statements whenever the TEMP database
    ** schema is changed.  Ticket #1644 */
    sqlite3ExpirePreparedStatements(db);
    p->expired = 0;
  }