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applied Mark Cave-Ayland's new patch that is a bit cleaner and has a

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user-defined FETCH limit for creating a histogram.


git-svn-id: http://svn.osgeo.org/postgis/trunk@232 b70326c6-7e19-0410-871a-916f4a2858ee
This commit is contained in:
David Blasby 2003-01-22 17:07:39 +00:00
parent a8ca9583d6
commit e1d087579d
1 changed files with 15 additions and 9 deletions
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24
postgis_estimate.c
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@ -302,6 +302,7 @@ Datum build_histogram2d(PG_FUNCTION_ARGS)
int sum_area_numb_new =0;
int bump=0;
int tuplimit = 500000; // No. of tuples returned on each cursor fetch
bool moredata;
void *SPIplan;
void *SPIportal;
@ -336,8 +337,8 @@ Datum build_histogram2d(PG_FUNCTION_ARGS)
columnname = DatumGetCString(DirectFunctionCall1(textout,
PointerGetDatum(PG_GETARG_DATUM(2))));
elog(NOTICE,"Start build_histogram2d with %i items already existing", sum_area_numb);
elog(NOTICE,"table=\"%s\", column = \"%s\"", tablename, columnname);
//elog(NOTICE,"Start build_histogram2d with %i items already existing", sum_area_numb);
//elog(NOTICE,"table=\"%s\", column = \"%s\"", tablename, columnname);
SPIcode = SPI_connect();
@ -352,7 +353,6 @@ Datum build_histogram2d(PG_FUNCTION_ARGS)
sprintf(sql,"SELECT box(\"%s\") FROM \"%s\"",columnname,tablename);
//elog(NOTICE,"executing %s",sql);
//SPIcode = SPI_exec(sql, 2147483640 ); // max signed int32
SPIplan = SPI_prepare(sql, 0, NULL);
if (SPIplan == NULL)
@ -368,19 +368,21 @@ Datum build_histogram2d(PG_FUNCTION_ARGS)
PG_RETURN_NULL() ;
}
//elog(NOTICE,"processing %i records",SPI_processed);
moredata = TRUE;
while (moredata==TRUE) {
SPI_cursor_fetch(SPIportal, TRUE, 50000);
//elog(NOTICE,"about to fetch...");
SPI_cursor_fetch(SPIportal, TRUE, tuplimit);
tuptable = SPI_tuptable;
tupdesc = SPI_tuptable->tupdesc;
ntuples = SPI_processed;
//elog(NOTICE,"processing %d records", ntuples);
if (ntuples > 0) {
tuptable = SPI_tuptable;
tupdesc = SPI_tuptable->tupdesc;
cell_area = ( (xmax-xmin)*(ymax-ymin)/(histo->boxesPerSide*histo->boxesPerSide) );
for (t=0;t<ntuples;t++)
@ -456,6 +458,10 @@ Datum build_histogram2d(PG_FUNCTION_ARGS)
} // End of for loop
// Free all the results after each fetch, otherwise all tuples stay
// in memory until the end of the table...
SPI_freetuptable(tuptable);
} else {
moredata = FALSE;
} // End of if ntuples > 0
@ -473,7 +479,7 @@ Datum build_histogram2d(PG_FUNCTION_ARGS)
PG_RETURN_NULL() ;
}
// elog(NOTICE,"finishing up build_histogram2d ");
//elog(NOTICE,"finishing up build_histogram2d ");
//pfree(tablename);
//pfree(columnname);