[TD-10998]<fix>: set default JSON string type to nchar

src/common/src/tglobal.c

@@ -289,7 +289,7 @@ char     Compressor[32] = "ZSTD_COMPRESSOR";  // ZSTD_COMPRESSOR or GZIP_COMPRES
 int8_t tsDeadLockKillQuery = 0;
 
 // default JSON string type
-char tsDefaultJSONStrType[7] = "binary";
+char tsDefaultJSONStrType[7] = "nchar";
 char tsSmlChildTableName[TSDB_TABLE_NAME_LEN] = ""; //user defined child table name can be specified in tag value. If set to empty system will generate table name using MD5 hash.
 
 int32_t (*monStartSystemFp)() = NULL;