meos_catalog.c File Reference

Create a cache of PostgreSQL type and operator Oids in global variable arrays to avoid (slow) lookups. More...

#include "pg_temporal/meos_catalog.h"
#include <postgres.h>
#include <miscadmin.h>
#include <access/genam.h>
#include <access/heapam.h>
#include <access/htup_details.h>
#include <access/tableam.h>
#include <catalog/indexing.h>
#include <catalog/namespace.h>
#include <catalog/pg_extension.h>
#include <commands/extension.h>
#include <common/hashfn.h>
#include <utils/fmgroids.h>
#include <utils/syscache.h>
#include <utils/rel.h>
#include <meos.h>
#include "temporal/meos_catalog.h"
#include "lib/simplehash.h"

Data Structures
struct	mobilitydb_constants
	Global variable that states whether the type and operator Oid caches have been initialized. More...
struct	oid_oper_entry
	Structure to represent the operator cache hash table. More...

Macros
#define	SH_DECLARE
#define	SH_DEFINE
#define	SH_ELEMENT_TYPE   oid_oper_entry
#define	SH_EQUAL(tb, a, b)   a == b
#define	SH_HASH_KEY(tb, key)   hash_bytes_uint32(key)
#define	SH_KEY   oproid
#define	SH_KEY_TYPE   Oid
#define	SH_PREFIX   opertable
	Define a hashtable mapping operator Oids to a structure containing operator and type numbers. More...
#define	SH_SCOPE   static inline

Functions
meosType	basetype_multirangetype (meosType type)
	Return the range type of a base type. More...
meosType	basetype_rangetype (meosType type)
	Return the range type of a base type. More...
bool	ensure_range_basetype (meosType type)
	Ensure that a type is a built-in PostgreSQL range type. More...
Datum	fill_oid_cache (PG_FUNCTION_ARGS)
	Function executed during the CREATE EXTENSION to precompute the operator cache and store it in table mobilitydb_opcache More...
static Oid	get_extension_schema (Oid ext_oid)
static mobilitydb_constants *	get_mobilitydb_constants ()
static bool	internal_type (const char *typname)
	Determine whether the type is an internal MobilityDB type. More...
static void	mobilitydb_initialize_cache ()
	Initialize Oid cache. More...
static Oid	mobilitydb_nsp_oid ()
	Return namespace Oid for the extension. More...
int	namestrcmp (Name name, const char *str)
meosOper	oid_oper (Oid oproid, meosType *ltype, meosType *rtype)
	Fetch from the hash table the operator info. More...
meosType	oid_type (Oid typid)
	Fetch from the cache the type number. More...
Oid	oper_oid (meosOper oper, meosType lt, meosType rt)
	Fetch from the cache the Oid of an operator. More...
bool	range_basetype (meosType type)
	Return true if the type is a base type of a built-in PostgreSQL range type. More...
static Oid	RelnameNspGetRelid (const char *relname, Oid nsp_oid)
	Utility call to lookup relation oid given name and nspoid. More...
Oid	type_oid (meosType type)
	Fetch from the cache the Oid of a type. More...
static Oid	TypenameNspGetTypid (const char *typname, Oid nsp_oid)
	Utility call to lookup type oid given name and nspoid. More...

Variables
mobilitydb_constants *	MOBILITYDB_CONSTANTS = NULL

Detailed Description

Create a cache of PostgreSQL type and operator Oids in global variable arrays to avoid (slow) lookups.

The arrays are initialized when the extension is loaded.

Estimating the selectivity of Boolean operators is essential for defining efficient queries execution plans. The extension defines several classes of Boolean operators (equal, less than, overlaps, ...), each of which has as left or right arguments a built-in type (such as integer, timestamptz, geometry, ...) or a type defined by the extension (such as tstzspan, tint, ...).

As of January 2023 there are 1470 operators defined in MobilityDB. We need to translate between operator Oid <-> MEOS operator info both ways. For Oid -> MEOS operator we use a hash table with Oid as key. For MEOS operator info -> Oid we use a three-dimensional array containing all possible combinations of operator/left argument/right argument. The invalid combinations are initialized to 0.