Datum
_ltree_compress(PG_FUNCTION_ARGS)
{
GISTENTRY *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
GISTENTRY *retval = entry;
if (entry->leafkey)
{ /* ltree */
ltree_gist *key;
ArrayType *val = DatumGetArrayTypeP(entry->key);
int32 len = LTG_HDRSIZE + ASIGLEN;
int num = ArrayGetNItems(ARR_NDIM(val), ARR_DIMS(val));
ltree *item = (ltree *) ARR_DATA_PTR(val);
if (ARR_NDIM(val) > 1)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array must be one-dimensional")));
if (array_contains_nulls(val))
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
errmsg("array must not contain nulls")));
key = (ltree_gist *) palloc(len);
SET_VARSIZE(key, len);
key->flag = 0;
MemSet(LTG_SIGN(key), 0, ASIGLEN);
while (num > 0)
{
hashing(LTG_SIGN(key), item);
num--;
item = NEXTVAL(item);
}
retval = (GISTENTRY *) palloc(sizeof(GISTENTRY));
gistentryinit(*retval, PointerGetDatum(key),
entry->rel, entry->page,
entry->offset, FALSE);
}
else if (!LTG_ISALLTRUE(entry->key))
{
int32 i,
len;
ltree_gist *key;
BITVECP sign = LTG_SIGN(DatumGetPointer(entry->key));
ALOOPBYTE
{
if ((sign[i] & 0xff) != 0xff)
PG_RETURN_POINTER(retval);
}
len = LTG_HDRSIZE;
key = (ltree_gist *) palloc(len);
SET_VARSIZE(key, len);
key->flag = LTG_ALLTRUE;
retval = (GISTENTRY *) palloc(sizeof(GISTENTRY));
gistentryinit(*retval, PointerGetDatum(key),
entry->rel, entry->page,
entry->offset, FALSE);
}
Datum geometry_estimated_extent(PG_FUNCTION_ARGS)
{
text *txnsp = NULL;
text *txtbl = NULL;
text *txcol = NULL;
char *nsp = NULL;
char *tbl = NULL;
char *col = NULL;
char *query;
ArrayType *array = NULL;
int SPIcode;
SPITupleTable *tuptable;
TupleDesc tupdesc ;
HeapTuple tuple ;
bool isnull;
GBOX *box;
size_t querysize;
GEOM_STATS geomstats;
float reltuples;
Datum binval;
if ( PG_NARGS() == 3 )
{
txnsp = PG_GETARG_TEXT_P(0);
txtbl = PG_GETARG_TEXT_P(1);
txcol = PG_GETARG_TEXT_P(2);
}
else if ( PG_NARGS() == 2 )
{
txtbl = PG_GETARG_TEXT_P(0);
txcol = PG_GETARG_TEXT_P(1);
}
else
{
elog(ERROR, "estimated_extent() called with wrong number of arguments");
PG_RETURN_NULL();
}
POSTGIS_DEBUG(2, "geomtery_estimated_extent called");
/* Connect to SPI manager */
SPIcode = SPI_connect();
if (SPIcode != SPI_OK_CONNECT)
{
elog(ERROR, "geometry_estimated_extent: couldnt open a connection to SPI");
PG_RETURN_NULL() ;
}
querysize = VARSIZE(txtbl)+VARSIZE(txcol)+516;
if ( txnsp )
{
nsp = text2cstring(txnsp);
querysize += VARSIZE(txnsp);
}
else
{
querysize += 32; /* current_schema() */
}
tbl = text2cstring(txtbl);
col = text2cstring(txcol);
#if POSTGIS_DEBUG_LEVEL > 0
if ( txnsp )
{
POSTGIS_DEBUGF(3, " schema:%s table:%s column:%s", nsp, tbl, col);
}
else
{
POSTGIS_DEBUGF(3, " schema:current_schema() table:%s column:%s",
tbl, col);
}
#endif
query = palloc(querysize);
/* Security check: because we access information in the pg_statistic table, we must run as the database
superuser (by marking the function as SECURITY DEFINER) and check permissions ourselves */
if ( txnsp )
{
sprintf(query, "SELECT has_table_privilege((SELECT usesysid FROM pg_user WHERE usename = session_user), '\"%s\".\"%s\"', 'select')", nsp, tbl);
}
else
{
sprintf(query, "SELECT has_table_privilege((SELECT usesysid FROM pg_user WHERE usename = session_user), '\"%s\"', 'select')", tbl);
}
POSTGIS_DEBUGF(4, "permission check sql query is: %s", query);
SPIcode = SPI_exec(query, 1);
if (SPIcode != SPI_OK_SELECT)
{
elog(ERROR, "geometry_estimated_extent: couldn't execute permission check sql via SPI");
SPI_finish();
PG_RETURN_NULL();
}
tuptable = SPI_tuptable;
tupdesc = SPI_tuptable->tupdesc;
tuple = tuptable->vals[0];
if (!DatumGetBool(SPI_getbinval(tuple, tupdesc, 1, &isnull)))
{
elog(ERROR, "geometry_estimated_extent: permission denied for relation %s", tbl);
SPI_finish();
PG_RETURN_NULL();
}
/* Return the stats data */
if ( txnsp )
{
sprintf(query,
"SELECT s.stanumbers1[5:8], c.reltuples FROM pg_class c"
" LEFT OUTER JOIN pg_namespace n ON (n.oid = c.relnamespace)"
" LEFT OUTER JOIN pg_attribute a ON (a.attrelid = c.oid )"
" LEFT OUTER JOIN pg_statistic s ON (s.starelid = c.oid AND "
"s.staattnum = a.attnum )"
" WHERE c.relname = '%s' AND a.attname = '%s' "
" AND n.nspname = '%s';",
tbl, col, nsp);
}
else
{
sprintf(query,
"SELECT s.stanumbers1[5:8], c.reltuples FROM pg_class c"
" LEFT OUTER JOIN pg_namespace n ON (n.oid = c.relnamespace)"
" LEFT OUTER JOIN pg_attribute a ON (a.attrelid = c.oid )"
" LEFT OUTER JOIN pg_statistic s ON (s.starelid = c.oid AND "
"s.staattnum = a.attnum )"
" WHERE c.relname = '%s' AND a.attname = '%s' "
" AND n.nspname = current_schema();",
tbl, col);
}
POSTGIS_DEBUGF(4, " query: %s", query);
SPIcode = SPI_exec(query, 1);
if (SPIcode != SPI_OK_SELECT )
{
elog(ERROR,"geometry_estimated_extent: couldnt execute sql via SPI");
SPI_finish();
PG_RETURN_NULL();
}
if (SPI_processed != 1)
{
POSTGIS_DEBUGF(3, " %d stat rows", SPI_processed);
elog(ERROR, "Unexistent field \"%s\".\"%s\".\"%s\"",
( nsp ? nsp : "<current>" ), tbl, col);
SPI_finish();
PG_RETURN_NULL() ;
}
tuptable = SPI_tuptable;
tupdesc = SPI_tuptable->tupdesc;
tuple = tuptable->vals[0];
/* Check if the table has zero rows first */
binval = SPI_getbinval(tuple, tupdesc, 2, &isnull);
if (isnull)
{
POSTGIS_DEBUG(3, " reltuples is NULL");
elog(ERROR, "geometry_estimated_extent: null reltuples for table");
SPI_finish();
PG_RETURN_NULL();
}
reltuples = DatumGetFloat4(binval);
if ( ! reltuples )
{
POSTGIS_DEBUG(3, "table has estimated zero rows");
/*
* TODO: distinguish between empty and not analyzed ?
*/
elog(NOTICE, "\"%s\".\"%s\".\"%s\" is empty or not analyzed",
( nsp ? nsp : "<current>" ), tbl, col);
SPI_finish();
PG_RETURN_NULL();
}
binval = SPI_getbinval(tuple, tupdesc, 1, &isnull);
if (isnull)
{
POSTGIS_DEBUG(3, " stats are NULL");
elog(ERROR, "geometry_estimated_extent: null statistics for table");
SPI_finish();
PG_RETURN_NULL();
}
array = DatumGetArrayTypeP(binval);
if ( ArrayGetNItems(ARR_NDIM(array), ARR_DIMS(array)) != 4 )
{
elog(ERROR, " corrupted histogram");
PG_RETURN_NULL();
}
POSTGIS_DEBUGF(3, " stats array has %d elems", ArrayGetNItems(ARR_NDIM(array), ARR_DIMS(array)));
/*
* Construct GBOX.
* Must allocate this in upper executor context
* to keep it alive after SPI_finish().
*/
box = SPI_palloc(sizeof(GBOX));
FLAGS_SET_GEODETIC(box->flags, 0);
FLAGS_SET_Z(box->flags, 0);
FLAGS_SET_M(box->flags, 0);
/* Construct the box */
memcpy(&(geomstats.xmin), ARR_DATA_PTR(array), sizeof(float)*4);
box->xmin = geomstats.xmin;
box->xmax = geomstats.xmax;
box->ymin = geomstats.ymin;
box->ymax = geomstats.ymax;
POSTGIS_DEBUGF(3, " histogram extent = %g %g, %g %g", box->xmin,
box->ymin, box->xmax, box->ymax);
SPIcode = SPI_finish();
if (SPIcode != SPI_OK_FINISH )
{
elog(ERROR, "geometry_estimated_extent: couldn't disconnect from SPI");
}
/* TODO: enlarge the box by some factor */
PG_RETURN_POINTER(box);
}