Github user xwq commented on a diff in the pull request:

    https://github.com/apache/incubator-trafodion/pull/513#discussion_r65540065
  
    --- Diff: core/conn/odbc/src/odbc/nsksrvrcore/srvrothers.cpp ---
    @@ -4811,6 +4811,64 @@ odbc_SQLSvc_GetSQLCatalogs_sme_(
     
                        break;
     
    +        case SQL_API_SQLSTATISTICS:
    +            if (!checkIfWildCard(catalogNm, catalogNmNoEsc) && !metadataId)
    +            {
    +                exception_->exception_nr = 
odbc_SQLSvc_GetSQLCatalogs_ParamError_exn_;
    +                exception_->u.ParamError.ParamDesc = 
SQLSVC_EXCEPTION_WILDCARD_NOT_SUPPORTED;
    +            }
    +            if (tableNm[0] != '$' && tableNm[0] != '\\')
    +            {
    +                if (strcmp(catalogNm, "") == 0)
    +                    strcpy(tableName1, SEABASE_MD_CATALOG);
    +                else
    +                    strcpy(tableName1, catalogNm);
    +            }
    +
    +            tableParam[0] = tableName1;
    +            convertWildcard(metadataId, TRUE, schemaNm, expSchemaNm);
    +            convertWildcardNoEsc(metadataId, TRUE, schemaNm, 
schemaNmNoEsc);
    +            convertWildcard(metadataId, TRUE, tableNm, expTableNm);
    +            convertWildcardNoEsc(metadataId, TRUE, tableNmNoEsc, 
tableNmNoEsc);
    +            inputParam[0] = schemaNmNoEsc;
    +            inputParam[1] = expSchemaNm;
    +            inputParam[2] = tableNmNoEsc;
    +            inputParam[3] = expTableNm;
    +
    +            snprintf(CatalogQuery, sizeof(CatalogQuery),
    +                    "select "
    +                    "cast('%s' as varchar(128)) TABLE_CAT, "
    +                    "cast(trim(ob.SCHEMA_NAME) as varchar(128)) 
TABLE_SCHEM, "
    +                    "cast(trim(ob.OBJECT_NAME) as varchar(128)) 
TABLE_NAME, "
    +                    "cast(0 as smallint) NON_UNIQUE, " // not support
    +                    "cast('' as varchar(128)) INDEX_QUALIFIER, " // not 
support
    +                    "cast('' as varchar(128)) INDEX_NAME, "
    +                    "cast(0 as smallint) TYPE, " // not support
    +                    "cast((case when (trim(co.COLUMN_CLASS) <> 'S') then 
co.column_number+1 else "
    +                        "co.column_number end) as smallint) 
ORDINAL_POSITION, "
    +                    "cast(trim(co.COLUMN_NAME) as varchar(128)) 
COLUMN_NAME, "
    +                    "cast('' as char(1)) ASC_OR_DES, "
    +                    "cast(sb.rowcount as integer) CARDINALITY, "
    +                    "cast(0 as integer) PAGES, " // not support
    +                    "cast('' as varchar(128)) FILTER_CONDITION " // not 
support
    +                    "from "
    +                    "TRAFODION.\"_MD_\".OBJECTS ob, "
    +                    "TRAFODION.\"_MD_\".COLUMNS co, "
    +                    "TRAFODION.%s.sb_histograms sb "
    +                    "where "
    +                    "ob.OBJECT_UID = co.OBJECT_UID "
    +                    "and co.COLUMN_NUMBER = sb.COLUMN_NUMBER "
    --- End diff --
    
    Thanks Dave, I miss "co.OBJECT_UID=sb.TABLE_UID", I will add this.
    
    For mutlit-column histograms, I don't known the exactly behavior. I will 
take some time to investigate it. 
    
    Actually , I can't find the  document for metadata and histograms. I am 
studying through learning the query for other catalog API.  So this question 
maybe has many issues, and there are many result it can't support now.  I think 
your comments will help me studying them.


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