1/*-------------------------------------------------------------------------
4 * Server Programming Interface private declarations
6 * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
9 * src/include/executor/spi_priv.h
11 *-------------------------------------------------------------------------
20 #define _SPI_PLAN_MAGIC 569278163
28 /* subtransaction in which current Executor call was started */
31 /* resources of this execution context */
39 /* transaction management support */
40 bool atomic;
/* atomic execution context, does not allow
45 /* saved values of API global variables for previous nesting level */
52 * SPI plans have three states: saved, unsaved, or temporary.
54 * Ordinarily, the _SPI_plan struct itself as well as the argtypes array
55 * are in a dedicated memory context identified by plancxt (which can be
56 * really small). All the other subsidiary state is in plancache entries
57 * identified by plancache_list (note: the list cells themselves are in
60 * In an unsaved plan, the plancxt as well as the plancache entries' contexts
61 * are children of the SPI procedure context, so they'll all disappear at
62 * function exit. plancache.c also knows that the plancache entries are
63 * "unsaved", so it doesn't link them into its global list; hence they do
64 * not respond to inval events. This is OK since we are presumably holding
65 * adequate locks to prevent other backends from messing with the tables.
67 * For a saved plan, the plancxt is made a child of CacheMemoryContext
68 * since it should persist until explicitly destroyed. Likewise, the
69 * plancache entries will be under CacheMemoryContext since we tell
70 * plancache.c to save them. We rely on plancache.c to keep the cache
71 * entries up-to-date as needed in the face of invalidation events.
73 * There are also "temporary" SPI plans, in which the _SPI_plan struct is
74 * not even palloc'd but just exists in some function's local variable.
75 * The plancache entries are unsaved and exist under the SPI executor context,
76 * while additional data such as argtypes and list cells is loose in the SPI
77 * executor context. Such plans can be identified by having plancxt == NULL.
79 * We can also have "one-shot" SPI plans (which are typically temporary,
80 * as described above). These are meant to be executed once and discarded,
81 * and various optimizations are made on the assumption of single use.
82 * Note in particular that the CachedPlanSources within such an SPI plan
83 * are not "complete" until execution.
85 * Note: if the original query string contained only whitespace and comments,
86 * the plancache_list will be NIL and so there is no place to store the
87 * query string. We don't care about that, but we do care about the
88 * argument type array, which is why it's seemingly-redundantly stored.
92 int magic;
/* should equal _SPI_PLAN_MAGIC */
93 bool saved;
/* saved or unsaved plan? */
99 int nargs;
/* number of plan arguments */
105#endif /* SPI_PRIV_H */
void(* ParserSetupHook)(ParseState *pstate, void *arg)
struct _SPI_plan _SPI_plan
SubTransactionId connectSubid
SPITupleTable * outer_tuptable
QueryEnvironment * queryEnv
SubTransactionId execSubid
ParserSetupHook parserSetup