Removed the learn_cache routine.

Now it is not needed, because non-transactional storage is used.

Author: Daniil Anisimov

Diff for: Makefile

@@ -7,7 +7,7 @@ MODULE_big = aqo
 OBJS = $(WIN32RES) \
 	aqo.o auto_tuning.o cardinality_estimation.o cardinality_hooks.o \
 	hash.o machine_learning.o path_utils.o postprocessing.o preprocessing.o \
-	selectivity_cache.o storage.o utils.o learn_cache.o aqo_shared.o
+	selectivity_cache.o storage.o utils.o aqo_shared.o
 
 TAP_TESTS = 1
 

Diff for: aqo.c

@@ -26,7 +26,6 @@
 #include "path_utils.h"
 #include "postmaster/bgworker.h"
 #include "preprocessing.h"
-#include "learn_cache.h"
 #include "storage.h"
 
 
@@ -322,7 +321,7 @@ _PG_init(void)
 							 PGC_USERSET,
 							 0,
 							 NULL,
-							 lc_assign_hook,
+							 NULL,
 							 NULL
 	);
 

Diff for: aqo.h

@@ -174,6 +174,7 @@ extern bool aqo_show_hash;
 extern bool aqo_show_details;
 extern int aqo_join_threshold;
 extern bool use_wide_search;
+extern bool aqo_learn_statement_timeout;
 
 /* Parameters for current query */
 typedef struct QueryContextData
@@ -256,10 +257,8 @@ int get_clause_hash(Expr *clause, int nargs, int *args_hash, int *eclass_hash);
 
 
 /* Storage interaction */
-extern bool load_fss_ext(uint64 fs, int fss, OkNNrdata *data, List **reloids,
-						 bool isSafe);
-extern bool update_fss_ext(uint64 fs, int fss, OkNNrdata *data,
-						   List *reloids, bool isTimedOut);
+extern bool load_fss_ext(uint64 fs, int fss, OkNNrdata *data, List **reloids);
+extern bool update_fss_ext(uint64 fs, int fss, OkNNrdata *data, List *reloids);
 
 /* Query preprocessing hooks */
 extern void print_into_explain(PlannedStmt *plannedstmt, IntoClause *into,

Diff for: aqo_shared.c

@@ -12,161 +12,13 @@
 #include "storage.h"
 
 
-typedef struct
-{
-	int		magic;
-	uint32	total_size;
-	uint32	delta;
-} dsm_seg_hdr;
-
-#define free_space(hdr) (uint32) (temp_storage_size - sizeof(dsm_seg_hdr) - hdr->delta)
-#define addr(delta)	((char *) dsm_segment_address(seg) + sizeof(dsm_seg_hdr) + delta)
-
 shmem_startup_hook_type prev_shmem_startup_hook = NULL;
 AQOSharedState *aqo_state = NULL;
-HTAB *fss_htab = NULL;
-static int aqo_htab_max_items = 1000;
 int fs_max_items = 10000; /* Max number of different feature spaces in ML model */
 int fss_max_items = 100000; /* Max number of different feature subspaces in ML model */
-static uint32 temp_storage_size = 1024 * 1024 * 10; /* Storage size, in bytes */
-static dsm_segment *seg = NULL;
-
 
-static void aqo_detach_shmem(int code, Datum arg);
 static void on_shmem_shutdown(int code, Datum arg);
 
-
-void *
-get_dsm_all(uint32 *size)
-{
-	dsm_seg_hdr	*hdr;
-
-	Assert(LWLockHeldByMeInMode(&aqo_state->lock, LW_EXCLUSIVE));
-
-	if (aqo_state->dsm_handler == DSM_HANDLE_INVALID)
-	{
-		/* Fast path. No any cached data exists. */
-		*size = 0;
-		return NULL;
-	}
-
-	if (!seg)
-	{
-		/* if segment exists we should connect to */
-		seg = dsm_attach(aqo_state->dsm_handler);
-		Assert(seg);
-		dsm_pin_mapping(seg);
-		before_shmem_exit(aqo_detach_shmem, (Datum) &aqo_state->dsm_handler);
-	}
-
-	hdr = (dsm_seg_hdr	*) dsm_segment_address(seg);
-	*size = hdr->delta;
-	return (char *) hdr + sizeof(dsm_seg_hdr);
-}
-
-/*
- * Cleanup of DSM cache: set header into default state and zero the memory block.
- * This operation can be coupled with the cache dump, so we do it under an external
- * hold of the lock.
- */
-void
-reset_dsm_cache(void)
-{
-	dsm_seg_hdr	*hdr;
-	char		*start;
-
-	Assert(LWLockHeldByMeInMode(&aqo_state->lock, LW_EXCLUSIVE));
-
-	if (aqo_state->dsm_handler == DSM_HANDLE_INVALID || !seg)
-		/* Fast path. No any cached data exists. */
-		return;
-
-	hdr = (dsm_seg_hdr *) dsm_segment_address(seg);
-	start = (char *) hdr + sizeof(dsm_seg_hdr);
-
-	/* Reset the cache */
-	memset(start, 0, hdr->delta);
-
-	hdr->delta = 0;
-	hdr->total_size = temp_storage_size - sizeof(dsm_seg_hdr);
-}
-
-char *
-get_cache_address(void)
-{
-	dsm_seg_hdr *hdr;
-
-	Assert(LWLockHeldByMeInMode(&aqo_state->lock, LW_EXCLUSIVE) ||
-		   LWLockHeldByMeInMode(&aqo_state->lock, LW_SHARED));
-
-	if (aqo_state->dsm_handler != DSM_HANDLE_INVALID)
-	{
-		if (!seg)
-		{
-			/* Another process created the segment yet. Just attach to. */
-			seg = dsm_attach(aqo_state->dsm_handler);
-			dsm_pin_mapping(seg);
-			before_shmem_exit(aqo_detach_shmem, (Datum) &aqo_state->dsm_handler);
-		}
-
-		hdr = (dsm_seg_hdr	*) dsm_segment_address(seg);
-	}
-	else
-	{
-		/*
-		 * First request for DSM cache in this instance.
-		 * Create the DSM segment. Pin it to live up to instance shutdown.
-		 * Don't forget to detach DSM segment before an exit.
-		 */
-		seg = dsm_create(temp_storage_size, 0);
-		dsm_pin_mapping(seg);
-		dsm_pin_segment(seg);
-		aqo_state->dsm_handler = dsm_segment_handle(seg);
-		before_shmem_exit(aqo_detach_shmem, (Datum) &aqo_state->dsm_handler);
-
-		hdr = (dsm_seg_hdr *) dsm_segment_address(seg);
-		hdr->magic = AQO_SHARED_MAGIC;
-		hdr->delta = 0;
-		hdr->total_size = temp_storage_size - sizeof(dsm_seg_hdr);
-	}
-
-	Assert(seg);
-	Assert(hdr->magic == AQO_SHARED_MAGIC && hdr->total_size > 0);
-
-	return (char *) hdr + sizeof(dsm_seg_hdr);
-}
-
-uint32
-get_dsm_cache_pos(uint32 size)
-{
-	dsm_seg_hdr	   *hdr;
-	uint32			pos;
-
-	Assert(LWLockHeldByMeInMode(&aqo_state->lock, LW_EXCLUSIVE) ||
-		   LWLockHeldByMeInMode(&aqo_state->lock, LW_SHARED));
-
-	(void) get_cache_address();
-	hdr = (dsm_seg_hdr	*) dsm_segment_address(seg);
-
-	if (free_space(hdr) < size || size == 0)
-		elog(ERROR,
-			 "DSM cache can't allcoate a mem block. Required: %u, free: %u",
-			 size, free_space(hdr));
-
-	pos = hdr->delta;
-	hdr->delta += size;
-	Assert(free_space(hdr) >= 0);
-	return pos;
-}
-
-static void
-aqo_detach_shmem(int code, Datum arg)
-{
-	if (seg != NULL)
-		dsm_detach(seg);
-	seg = NULL;
-}
-
 void
 aqo_init_shmem(void)
 {
@@ -177,7 +29,6 @@ aqo_init_shmem(void)
 		prev_shmem_startup_hook();
 
 	aqo_state = NULL;
-	fss_htab = NULL;
 	stat_htab = NULL;
 	qtexts_htab = NULL;
 	data_htab = NULL;
@@ -189,7 +40,6 @@ aqo_init_shmem(void)
 	{
 		/* First time through ... */
 
-		aqo_state->dsm_handler = DSM_HANDLE_INVALID;
 		aqo_state->qtexts_dsa_handler = DSM_HANDLE_INVALID;
 		aqo_state->data_dsa_handler = DSM_HANDLE_INVALID;
 
@@ -208,13 +58,6 @@ aqo_init_shmem(void)
 		LWLockInitialize(&aqo_state->queries_lock, LWLockNewTrancheId());
 	}
 
-	info.keysize = sizeof(htab_key);
-	info.entrysize = sizeof(htab_entry);
-	fss_htab = ShmemInitHash("AQO hash",
-							  aqo_htab_max_items, aqo_htab_max_items,
-							  &info,
-							  HASH_ELEM | HASH_BLOBS);
-
 	info.keysize = sizeof(((StatEntry *) 0)->queryid);
 	info.entrysize = sizeof(StatEntry);
 	stat_htab = ShmemInitHash("AQO Stat HTAB", fs_max_items, fs_max_items,
@@ -280,7 +123,6 @@ aqo_memsize(void)
 	Size		size;
 
 	size = MAXALIGN(sizeof(AQOSharedState));
-	size = add_size(size, hash_estimate_size(aqo_htab_max_items, sizeof(htab_entry)));
 	size = add_size(size, hash_estimate_size(fs_max_items, sizeof(AQOSharedState)));
 	size = add_size(size, hash_estimate_size(fs_max_items, sizeof(StatEntry)));
 	size = add_size(size, hash_estimate_size(fs_max_items, sizeof(QueryTextEntry)));

Diff for: aqo_shared.h

@@ -10,23 +10,9 @@
 
 #define AQO_SHARED_MAGIC	0x053163
 
-typedef struct
-{
-	/* XXX we assume this struct contains no padding bytes */
-	uint64	fs;
-	int64	fss;
-} htab_key;
-
-typedef struct
-{
-	htab_key	key;
-	uint32		hdr_off; /* offset of data in DSM cache */
-} htab_entry;
-
 typedef struct AQOSharedState
 {
 	LWLock		lock;			/* mutual exclusion */
-	dsm_handle	dsm_handler;
 
 	/* Storage fields */
 	LWLock		stat_lock; /* lock for access to stat storage */
@@ -50,16 +36,11 @@ typedef struct AQOSharedState
 
 extern shmem_startup_hook_type prev_shmem_startup_hook;
 extern AQOSharedState *aqo_state;
-extern HTAB *fss_htab;
 
 extern int fs_max_items; /* Max number of feature spaces that AQO can operate */
 extern int fss_max_items;
 
 extern Size aqo_memsize(void);
-extern void reset_dsm_cache(void);
-extern void *get_dsm_all(uint32 *size);
-extern char *get_cache_address(void);
-extern uint32 get_dsm_cache_pos(uint32 size);
 extern void aqo_init_shmem(void);
 
 #endif /* AQO_SHARED_H */

Diff for: cardinality_estimation.c

@@ -81,7 +81,7 @@ predict_for_relation(List *clauses, List *selectivities, List *relsigns,
 							  &ncols, &features);
 	data = OkNNr_allocate(ncols);
 
-	if (load_fss_ext(query_context.fspace_hash, *fss, data, NULL, true))
+	if (load_fss_ext(query_context.fspace_hash, *fss, data, NULL))
 		result = OkNNr_predict(data, features);
 	else
 	{

Diff for: cardinality_hooks.c

@@ -452,7 +452,7 @@ predict_num_groups(PlannerInfo *root, Path *subpath, List *group_exprs,
 	*fss = get_grouped_exprs_hash(child_fss, group_exprs);
 	memset(&data, 0, sizeof(OkNNrdata));
 
-	if (!load_fss_ext(query_context.fspace_hash, *fss, &data, NULL, true))
+	if (!load_fss_ext(query_context.fspace_hash, *fss, &data, NULL))
 		return -1;
 
 	Assert(data.rows == 1);

Diff for: expected/statement_timeout.out

@@ -111,6 +111,29 @@ SELECT check_estimated_rows('SELECT *, pg_sleep(1) FROM t;');
                     5
 (1 row)
 
+-- Interrupted query should immediately appear in aqo_data
+SELECT 1 FROM aqo_reset();
+ ?column? 
+----------
+        1
+(1 row)
+
+SET statement_timeout = 500;
+SELECT count(*) FROM aqo_data; -- Must be zero
+ count 
+-------
+     0
+(1 row)
+
+SELECT x, pg_sleep(0.1) FROM t WHERE x > 0;
+NOTICE:  [AQO] Time limit for execution of the statement was expired. AQO tried to learn on partial data.
+ERROR:  canceling statement due to statement timeout
+SELECT count(*) FROM aqo_data; -- Must be one
+ count 
+-------
+     1
+(1 row)
+
 SELECT 1 FROM aqo_reset();
  ?column? 
 ----------