{ SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE,      SQLITE_NoCkptOnClose  },
        { SQLITE_DBCONFIG_ENABLE_QPSG,           SQLITE_EnableQPSG     },
        { SQLITE_DBCONFIG_TRIGGER_EQP,           SQLITE_TriggerEQP     },
        { SQLITE_DBCONFIG_RESET_DATABASE,        SQLITE_ResetDatabase  },
        { SQLITE_DBCONFIG_DEFENSIVE,             SQLITE_Defensive      },
        { SQLITE_DBCONFIG_WRITABLE_SCHEMA,       SQLITE_WriteSchema|
                                                 SQLITE_NoSchemaError  },
        { SQLITE_DBCONFIG_LEGACY_ALTER_TABLE,    SQLITE_LegacyAlter    },
        { SQLITE_DBCONFIG_DQS_DDL,               SQLITE_DqsDDL         },
        { SQLITE_DBCONFIG_DQS_DML,               SQLITE_DqsDML         },
      };
      unsigned int i;
      rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
      for(i=0; i<ArraySize(aFlagOp); i++){
        if( aFlagOp[i].op==op ){
          int onoff = va_arg(ap, int);
          int *pRes = va_arg(ap, int*);

  db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
  db->autoCommit = 1;
  db->nextAutovac = -1;
  db->szMmap = sqlite3GlobalConfig.szMmap;
  db->nextPagesize = 0;
  db->nMaxSorterMmap = 0x7FFFFFFF;
  db->flags |= SQLITE_ShortColNames | SQLITE_EnableTrigger | SQLITE_CacheSpill
                 | SQLITE_DqsDML
#if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
                 | SQLITE_AutoIndex
#endif
#if SQLITE_DEFAULT_CKPTFULLFSYNC
                 | SQLITE_CkptFullFSync
#endif
#if SQLITE_DEFAULT_FILE_FORMAT<4

  }
  zSpan += n+1;
  if( zCol && sqlite3StrICmp(zSpan, zCol)!=0 ){
    return 0;
  }
  return 1;
}

/*
** Return TRUE if the double-quoted string  mis-feature should be supported.
*/
static int areDoubleQuotedStringsEnabled(sqlite3 *db, NameContext *pTopNC){
  if( db->init.busy ) return 1;  /* Always support for legacy schemas */
  if( pTopNC->ncFlags & NC_IsDDL ){
    /* Currently parsing a DDL statement */
    if( sqlite3WritableSchema(db) && (db->flags & SQLITE_DqsDML)!=0 ){
      return 1;
    }
    return (db->flags & SQLITE_DqsDDL)!=0;
  }else{
    /* Currently parsing a DML statement */
    return (db->flags & SQLITE_DqsDML)!=0;
  }
}

/*
** Given the name of a column of the form X.Y.Z or Y.Z or just Z, look up
** that name in the set of source tables in pSrcList and make the pExpr 
** expression node refer back to that source column.  The following changes
** are made to pExpr:
**

  ** pExpr.
  **
  ** Because no reference was made to outer contexts, the pNC->nRef
  ** fields are not changed in any context.
  */
  if( cnt==0 && zTab==0 ){
    assert( pExpr->op==TK_ID );
    if( ExprHasProperty(pExpr,EP_DblQuoted)
     && areDoubleQuotedStringsEnabled(db, pTopNC)
    ){
      /* If a double-quoted identifier does not match any known column name,
      ** then treat it as a string.
      **
      ** This hack was added in the early days of SQLite in a misguided attempt
      ** to be compatible with MySQL 3.x, which used double-quotes for strings.
      ** I now sorely regret putting in this hack. The effect of this hack is

    sSrc.nSrc = 1;
    sSrc.a[0].zName = pTab->zName;
    sSrc.a[0].pTab = pTab;
    sSrc.a[0].iCursor = -1;
  }
  sNC.pParse = pParse;
  sNC.pSrcList = &sSrc;
  sNC.ncFlags = type | NC_IsDDL;



  if( (rc = sqlite3ResolveExprNames(&sNC, pExpr))!=SQLITE_OK ) return rc;
  if( pList ) rc = sqlite3ResolveExprListNames(&sNC, pList);
  return rc;
}

  }else

  if( c=='d' && n>=3 && strncmp(azArg[0], "dbconfig", n)==0 ){
    static const struct DbConfigChoices {
      const char *zName;
      int op;
    } aDbConfig[] = {
        { "enable_fkey",        SQLITE_DBCONFIG_ENABLE_FKEY           },
        { "enable_trigger",     SQLITE_DBCONFIG_ENABLE_TRIGGER        },
        { "fts3_tokenizer",     SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER },
        { "load_extension",     SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION },
        { "no_ckpt_on_close",   SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE      },
        { "enable_qpsg",        SQLITE_DBCONFIG_ENABLE_QPSG           },
        { "trigger_eqp",        SQLITE_DBCONFIG_TRIGGER_EQP           },
        { "reset_database",     SQLITE_DBCONFIG_RESET_DATABASE        },
        { "defensive",          SQLITE_DBCONFIG_DEFENSIVE             },
        { "wriable_schema",     SQLITE_DBCONFIG_WRITABLE_SCHEMA       },
        { "legacy_alter_table", SQLITE_DBCONFIG_LEGACY_ALTER_TABLE    },
        { "dqs_dml",            SQLITE_DBCONFIG_DQS_DML               },
        { "dqs_ddl",            SQLITE_DBCONFIG_DQS_DDL               },
    };
    int ii, v;
    open_db(p, 0);
    for(ii=0; ii<ArraySize(aDbConfig); ii++){
      if( nArg>1 && strcmp(azArg[1], aDbConfig[ii].zName)!=0 ) continue;
      if( nArg>=3 ){
        sqlite3_db_config(p->db, aDbConfig[ii].op, booleanValue(azArg[2]), 0);

** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
** The first argument to this setting is an integer which is 0 to disable 
** the writable_schema, positive to enable writable_schema, or negative to
** leave the setting unchanged. The second parameter is a pointer to an
** integer into which is written 0 or 1 to indicate whether the writable_schema
** is enabled or disabled following this call.
** </dd>
**
** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
** the legacy behavior of the [ALTER TABLE RENAME] command such it
** behaves as it did prior to [version 3.24.0] (2018-06-04).  See the
** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
** additional information. This feature can also be turned on and off
** using the [PRAGMA legacy_alter_table] statement.
** </dd>
**
** [[SQLITE_DBCONFIG_DQS_DML]]
** <dt>SQLITE_DBCONFIG_DQS_DML</td>
** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
** the legacy [double-quoted string literal] misfeature for DML statement
** only, that is DELETE, INSERT, SELECT, and UPDATE statements.
** </dd>
**
** [[SQLITE_DBCONFIG_DQS_DDL]]
** <dt>SQLITE_DBCONFIG_DQS_DDL</td>
** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
** the legacy [double-quoted string literal] misfeature for DDL statements,
** such as CREATE TABLE and CREATE INDEX.
** </dd>
** </dl>
*/
#define SQLITE_DBCONFIG_MAINDBNAME            1000 /* const char* */
#define SQLITE_DBCONFIG_LOOKASIDE             1001 /* void* int int */
#define SQLITE_DBCONFIG_ENABLE_FKEY           1002 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_TRIGGER        1003 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE      1006 /* int int* */
#define SQLITE_DBCONFIG_ENABLE_QPSG           1007 /* int int* */
#define SQLITE_DBCONFIG_TRIGGER_EQP           1008 /* int int* */
#define SQLITE_DBCONFIG_RESET_DATABASE        1009 /* int int* */
#define SQLITE_DBCONFIG_DEFENSIVE             1010 /* int int* */
#define SQLITE_DBCONFIG_WRITABLE_SCHEMA       1011 /* int int* */
#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE    1012 /* int int* */
#define SQLITE_DBCONFIG_DQS_DML               1013 /* int int* */
#define SQLITE_DBCONFIG_DQS_DDL               1014 /* int int* */
#define SQLITE_DBCONFIG_MAX                   1014 /* Largest DBCONFIG */

/*
** CAPI3REF: Enable Or Disable Extended Result Codes
** METHOD: sqlite3
**
** ^The sqlite3_extended_result_codes() routine enables or disables the
** [extended result codes] feature of SQLite. ^The extended result

#define SQLITE_Fts3Tokenizer  0x00400000  /* Enable fts3_tokenizer(2) */
#define SQLITE_EnableQPSG     0x00800000  /* Query Planner Stability Guarantee*/
#define SQLITE_TriggerEQP     0x01000000  /* Show trigger EXPLAIN QUERY PLAN */
#define SQLITE_ResetDatabase  0x02000000  /* Reset the database */
#define SQLITE_LegacyAlter    0x04000000  /* Legacy ALTER TABLE behaviour */
#define SQLITE_NoSchemaError  0x08000000  /* Do not report schema parse errors*/
#define SQLITE_Defensive      0x10000000  /* Input SQL is likely hostile */
#define SQLITE_DqsDDL         0x20000000  /* dbl-quoted strings allowed in DDL*/
#define SQLITE_DqsDML         0x40000000  /* dbl-quoted strings allowed in DML*/

/* Flags used only if debugging */
#define HI(X)  ((u64)(X)<<32)
#ifdef SQLITE_DEBUG
#define SQLITE_SqlTrace       HI(0x0001)  /* Debug print SQL as it executes */
#define SQLITE_VdbeListing    HI(0x0002)  /* Debug listings of VDBE progs */
#define SQLITE_VdbeTrace      HI(0x0004)  /* True to trace VDBE execution */

#define NC_UEList    0x0080  /* True if uNC.pEList is used */
#define NC_UAggInfo  0x0100  /* True if uNC.pAggInfo is used */
#define NC_UUpsert   0x0200  /* True if uNC.pUpsert is used */
#define NC_MinMaxAgg 0x1000  /* min/max aggregates seen.  See note above */
#define NC_Complex   0x2000  /* True if a function or subquery seen */
#define NC_AllowWin  0x4000  /* Window functions are allowed here */
#define NC_HasWin    0x8000  /* One or more window functions seen */
#define NC_IsDDL    0x10000  /* Resolving names in a CREATE statement */


/*
** An instance of the following object describes a single ON CONFLICT
** clause in an upsert.
**
** The pUpsertTarget field is only set if the ON CONFLICT clause includes
** conflict-target clause.  (In "ON CONFLICT(a,b)" the "(a,b)" is the

  int objc,
  Tcl_Obj *CONST objv[]
){
  static const struct {
    const char *zName;
    int eVal;
  } aSetting[] = {
    { "FKEY",               SQLITE_DBCONFIG_ENABLE_FKEY },
    { "TRIGGER",            SQLITE_DBCONFIG_ENABLE_TRIGGER },
    { "FTS3_TOKENIZER",     SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER },
    { "LOAD_EXTENSION",     SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION },
    { "NO_CKPT_ON_CLOSE",   SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE },
    { "QPSG",               SQLITE_DBCONFIG_ENABLE_QPSG },
    { "TRIGGER_EQP",        SQLITE_DBCONFIG_TRIGGER_EQP },
    { "RESET_DB",           SQLITE_DBCONFIG_RESET_DATABASE },
    { "DEFENSIVE",          SQLITE_DBCONFIG_DEFENSIVE },
    { "WRITABLE_SCHEMA",    SQLITE_DBCONFIG_WRITABLE_SCHEMA },
    { "LEGACY_ALTER_TABLE", SQLITE_DBCONFIG_LEGACY_ALTER_TABLE },
    { "DQS_DML",            SQLITE_DBCONFIG_DQS_DML },
    { "DQS_DDL",            SQLITE_DBCONFIG_DQS_DDL },
  };
  int i;
  int v;
  const char *zSetting;
  sqlite3 *db;

  if( objc!=4 ){