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Document get_call_result_type() and friends; mark TypeGetTupleDesc()
and RelationNameGetTupleDesc() as deprecated; remove uses of the latter in the contrib library. Along the way, clean up crosstab() code and documentation a little.
This commit is contained in:
Tom Lane
@ -51,8 +51,6 @@ static void validateConnectbyTupleDesc(TupleDesc tupdesc, bool show_branch, bool
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static bool compatCrosstabTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
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static bool compatConnectbyTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
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static void get_normal_pair(float8 *x1, float8 *x2);
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static TupleDesc make_crosstab_tupledesc(TupleDesc spi_tupdesc,
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int num_categories);
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static Tuplestorestate *connectby(char *relname,
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char *key_fld,
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char *parent_key_fld,
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@ -332,12 +330,14 @@ get_normal_pair(float8 *x1, float8 *x2)
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* NOTES:
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* 1. SQL result must be ordered by 1,2.
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* 2. The number of values columns depends on the tuple description
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* of the function's declared return type.
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* 2. Missing values (i.e. not enough adjacent rows of same rowid to
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* of the function's declared return type. The return type's columns
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* must match the datatypes of the SQL query's result. The datatype
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* of the category column can be anything, however.
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* 3. Missing values (i.e. not enough adjacent rows of same rowid to
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* fill the number of result values columns) are filled in with nulls.
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* 3. Extra values (i.e. too many adjacent rows of same rowid to fill
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* 4. Extra values (i.e. too many adjacent rows of same rowid to fill
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* the number of result values columns) are skipped.
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* 4. Rows with all nulls in the values columns are skipped.
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* 5. Rows with all nulls in the values columns are skipped.
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*/
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PG_FUNCTION_INFO_V1(crosstab);
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Datum
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@ -360,10 +360,7 @@ crosstab(PG_FUNCTION_ARGS)
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if (SRF_IS_FIRSTCALL())
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{
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char *sql = GET_STR(PG_GETARG_TEXT_P(0));
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Oid funcid = fcinfo->flinfo->fn_oid;
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Oid functypeid;
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char functyptype;
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TupleDesc tupdesc = NULL;
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TupleDesc tupdesc;
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int ret;
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int proc;
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@ -391,20 +388,23 @@ crosstab(PG_FUNCTION_ARGS)
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spi_tuptable = SPI_tuptable;
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spi_tupdesc = spi_tuptable->tupdesc;
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/*
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/*----------
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* The provided SQL query must always return three columns.
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*
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* 1. rowname the label or identifier for each row in the final
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* result 2. category the label or identifier for each column
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* in the final result 3. values the value for each column
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* in the final result
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* 1. rowname
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* the label or identifier for each row in the final result
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* 2. category
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* the label or identifier for each column in the final result
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* 3. values
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* the value for each column in the final result
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*----------
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*/
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if (spi_tupdesc->natts != 3)
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
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errmsg("invalid source data SQL statement"),
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errdetail("The provided SQL must return 3 " \
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" columns; rowid, category, and values.")));
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errdetail("The provided SQL must return 3 "
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"columns: rowid, category, and values.")));
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}
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else
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{
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@ -416,39 +416,31 @@ crosstab(PG_FUNCTION_ARGS)
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/* SPI switches context on us, so reset it */
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MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
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/* get the typeid that represents our return type */
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functypeid = get_func_rettype(funcid);
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/* check typtype to see if we have a predetermined return type */
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functyptype = get_typtype(functypeid);
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if (functyptype == 'c')
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/* get a tuple descriptor for our result type */
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switch (get_call_result_type(fcinfo, NULL, &tupdesc))
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{
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/* Build a tuple description for a named composite type */
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tupdesc = TypeGetTupleDesc(functypeid, NIL);
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}
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else if (functypeid == RECORDOID)
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{
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if (fcinfo->nargs != 2)
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case TYPEFUNC_COMPOSITE:
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/* success */
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break;
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case TYPEFUNC_RECORD:
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/* failed to determine actual type of RECORD */
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ereport(ERROR,
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(errcode(ERRCODE_SYNTAX_ERROR),
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errmsg("wrong number of arguments")));
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else
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{
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int num_categories = PG_GETARG_INT32(1);
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tupdesc = make_crosstab_tupledesc(spi_tupdesc, num_categories);
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}
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(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
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errmsg("function returning record called in context "
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"that cannot accept type record")));
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break;
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default:
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/* result type isn't composite */
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elog(ERROR, "return type must be a row type");
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break;
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}
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else
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ereport(ERROR,
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(errcode(ERRCODE_SYNTAX_ERROR),
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errmsg("return type must be a row type")));
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/* make sure we have a persistent copy of the tupdesc */
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tupdesc = CreateTupleDescCopy(tupdesc);
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/*
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* Check that return tupdesc is compatible with the one we got
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* from ret_relname, at least based on number and type of
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* attributes
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* Check that return tupdesc is compatible with the data we got
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* from SPI, at least based on number and type of attributes
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*/
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if (!compatCrosstabTupleDescs(tupdesc, spi_tupdesc))
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ereport(ERROR,
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@ -679,8 +671,8 @@ crosstab(PG_FUNCTION_ARGS)
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* 1. SQL result must be ordered by 1.
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* 2. The number of values columns depends on the tuple description
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* of the function's declared return type.
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* 2. Missing values (i.e. missing category) are filled in with nulls.
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* 3. Extra values (i.e. not in category results) are skipped.
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* 3. Missing values (i.e. missing category) are filled in with nulls.
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* 4. Extra values (i.e. not in category results) are skipped.
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*/
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PG_FUNCTION_INFO_V1(crosstab_hash);
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Datum
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@ -1628,52 +1620,6 @@ compatCrosstabTupleDescs(TupleDesc ret_tupdesc, TupleDesc sql_tupdesc)
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return true;
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}
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static TupleDesc
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make_crosstab_tupledesc(TupleDesc spi_tupdesc, int num_categories)
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{
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Form_pg_attribute sql_attr;
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Oid sql_atttypid;
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TupleDesc tupdesc;
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int natts;
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AttrNumber attnum;
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char attname[NAMEDATALEN];
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int i;
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/*
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* We need to build a tuple description with one column for the
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* rowname, and num_categories columns for the values. Each must be of
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* the same type as the corresponding spi result input column.
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*/
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natts = num_categories + 1;
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tupdesc = CreateTemplateTupleDesc(natts, false);
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/* first the rowname column */
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attnum = 1;
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sql_attr = spi_tupdesc->attrs[0];
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sql_atttypid = sql_attr->atttypid;
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strcpy(attname, "rowname");
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TupleDescInitEntry(tupdesc, attnum, attname, sql_atttypid,
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-1, 0);
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/* now the category values columns */
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sql_attr = spi_tupdesc->attrs[2];
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sql_atttypid = sql_attr->atttypid;
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for (i = 0; i < num_categories; i++)
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{
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attnum++;
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sprintf(attname, "category_%d", i + 1);
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TupleDescInitEntry(tupdesc, attnum, attname, sql_atttypid,
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-1, 0);
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}
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return tupdesc;
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}
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/*
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* Return a properly quoted literal value.
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* Uses quote_literal in quote.c
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