MuhammadTahaNaveed commented on code in PR #2376:
URL: https://github.com/apache/age/pull/2376#discussion_r3091327671
##########
src/backend/executor/cypher_merge.c:
##########
@@ -936,6 +937,10 @@ static void end_cypher_merge(CustomScanState *node)
/* increment the command counter */
CommandCounterIncrement();
+ /* invalidate VLE cache if merge created anything */
+ if (css->created_new_path)
+ increment_graph_version(css->graph_oid);
Review Comment:
missing braces {}
##########
src/backend/utils/adt/age_global_graph.c:
##########
@@ -21,14 +21,24 @@
#include "access/heapam.h"
#include "catalog/namespace.h"
+#include "commands/trigger.h"
#include "common/hashfn.h"
#include "commands/label_commands.h"
+#include "port/atomics.h"
+#include "storage/lwlock.h"
#include "utils/datum.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/snapmgr.h"
#include "utils/builtins.h"
+#if PG_VERSION_NUM >= 170000
Review Comment:
we do not use version macros
##########
src/backend/utils/adt/age_global_graph.c:
##########
@@ -1531,3 +1676,291 @@ Datum age_graph_stats(PG_FUNCTION_ARGS)
PG_RETURN_POINTER(agtype_value_to_agtype(result.res));
}
+
+/*
+ * ============================================================================
+ * Graph Version Counter Implementation
+ *
+ * Provides per-graph monotonic version counters in shared memory for
+ * cross-backend VLE cache invalidation. Three modes are supported:
+ *
+ * DSM (PG 17+): Uses GetNamedDSMSegment — works without shared_preload_libs
+ * SHMEM (PG <17): Uses shmem_request/startup hooks — needs shared_preload_libs
+ * SNAPSHOT: Falls back to original snapshot-based invalidation
+ * ============================================================================
+ */
+
+#if PG_VERSION_NUM >= 170000
+/*
+ * DSM path: GetNamedDSMSegment init callback.
+ * Called once when the DSM segment is first created.
+ */
+static void age_dsm_init_callback(void *ptr)
+{
+ GraphVersionState *state = (GraphVersionState *) ptr;
+
+ LWLockInitialize(&state->lock,
+ LWLockNewTrancheId());
+ LWLockRegisterTranche(state->lock.tranche, "age_graph_version");
+ state->num_entries = 0;
+ memset(state->entries, 0, sizeof(state->entries));
+}
+
+/*
+ * Get the shared GraphVersionState via DSM registry.
+ * The segment is created on first access and persists until server shutdown.
+ */
+static GraphVersionState *get_version_state_dsm(void)
+{
+ bool found;
+
+ return (GraphVersionState *)
+ GetNamedDSMSegment("age_graph_versions",
+ sizeof(GraphVersionState),
+ age_dsm_init_callback,
+ &found);
+}
+#endif /* PG_VERSION_NUM >= 170000 */
+
+/*
+ * SHMEM path: request and startup hooks for PG < 17.
+ * These are registered in _PG_init when shared_preload_libraries is used.
+ * On PG 17+, DSM is used instead and these functions are not called.
+ */
+#if PG_VERSION_NUM < 170000
+void age_graph_version_shmem_request(void)
+{
+ RequestAddinShmemSpace(MAXALIGN(sizeof(GraphVersionState)));
+}
+
+void age_graph_version_shmem_startup(void)
+{
+ bool found;
+
+ LWLockAcquire(AddinShmemInitLock, LW_EXCLUSIVE);
+
+ shmem_version_state =
+ (GraphVersionState *) ShmemInitStruct("AGE Graph Version State",
+ sizeof(GraphVersionState),
+ &found);
+ if (!found)
+ {
+ LWLockInitialize(&shmem_version_state->lock,
+ LWLockNewTrancheId());
+ LWLockRegisterTranche(shmem_version_state->lock.tranche,
+ "age_graph_version");
+ shmem_version_state->num_entries = 0;
+ memset(shmem_version_state->entries, 0,
+ sizeof(shmem_version_state->entries));
+ }
+
+ LWLockRelease(AddinShmemInitLock);
+}
+#endif /* PG_VERSION_NUM < 170000 */
+
+/*
+ * Detect which version mode to use. Called once per backend on first access.
+ * Emits a DEBUG1 log message indicating the chosen mode.
+ */
+static void detect_version_mode(void)
+{
+#if PG_VERSION_NUM >= 170000
Review Comment:
we do not use version macros
##########
src/backend/utils/adt/age_global_graph.c:
##########
@@ -1261,9 +1328,55 @@ Oid get_vertex_entry_label_table_oid(vertex_entry *ve)
return ve->vertex_label_table_oid;
}
+/*
+ * Fetch vertex properties on demand from the heap via stored TID.
+ *
+ * Returns a datumCopy of the properties in the current memory context.
+ * The caller does not need to free the result explicitly — it will be
+ * freed when the memory context is reset (typically the SRF multi-call
+ * context for VLE, which is cleaned up when the SRF completes).
+ *
+ * If the tuple is no longer visible (e.g., concurrent mutation between
+ * cache build and fetch), the version counter should have invalidated
+ * the cache. If we get here with a stale TID, it indicates a bug in
+ * the invalidation logic.
+ */
Datum get_vertex_entry_properties(vertex_entry *ve)
{
- return ve->vertex_properties;
+ Relation rel;
+ HeapTupleData tuple;
+ Buffer buffer;
+ Datum result = (Datum) 0;
+
+ rel = table_open(ve->vertex_label_table_oid, AccessShareLock);
+ tuple.t_self = ve->tid;
+
+ if (heap_fetch(rel, GetActiveSnapshot(), &tuple, &buffer, true))
+ {
+ TupleDesc tupdesc = RelationGetDescr(rel);
+ bool isnull;
+ Datum props;
+
+ /* properties is column 2 (1-indexed) */
+ props = heap_getattr(&tuple, 2, tupdesc, &isnull);
+ if (!isnull)
+ result = datumCopy(props, false, -1);
Review Comment:
missing braces {}
##########
src/backend/utils/adt/age_global_graph.c:
##########
@@ -1531,3 +1676,291 @@ Datum age_graph_stats(PG_FUNCTION_ARGS)
PG_RETURN_POINTER(agtype_value_to_agtype(result.res));
}
+
+/*
+ * ============================================================================
+ * Graph Version Counter Implementation
+ *
+ * Provides per-graph monotonic version counters in shared memory for
+ * cross-backend VLE cache invalidation. Three modes are supported:
+ *
+ * DSM (PG 17+): Uses GetNamedDSMSegment — works without shared_preload_libs
+ * SHMEM (PG <17): Uses shmem_request/startup hooks — needs shared_preload_libs
+ * SNAPSHOT: Falls back to original snapshot-based invalidation
+ * ============================================================================
+ */
+
+#if PG_VERSION_NUM >= 170000
+/*
+ * DSM path: GetNamedDSMSegment init callback.
+ * Called once when the DSM segment is first created.
+ */
+static void age_dsm_init_callback(void *ptr)
+{
+ GraphVersionState *state = (GraphVersionState *) ptr;
+
+ LWLockInitialize(&state->lock,
+ LWLockNewTrancheId());
+ LWLockRegisterTranche(state->lock.tranche, "age_graph_version");
+ state->num_entries = 0;
+ memset(state->entries, 0, sizeof(state->entries));
+}
+
+/*
+ * Get the shared GraphVersionState via DSM registry.
+ * The segment is created on first access and persists until server shutdown.
+ */
+static GraphVersionState *get_version_state_dsm(void)
+{
+ bool found;
+
+ return (GraphVersionState *)
+ GetNamedDSMSegment("age_graph_versions",
+ sizeof(GraphVersionState),
+ age_dsm_init_callback,
+ &found);
+}
+#endif /* PG_VERSION_NUM >= 170000 */
+
+/*
+ * SHMEM path: request and startup hooks for PG < 17.
+ * These are registered in _PG_init when shared_preload_libraries is used.
+ * On PG 17+, DSM is used instead and these functions are not called.
+ */
+#if PG_VERSION_NUM < 170000
+void age_graph_version_shmem_request(void)
+{
+ RequestAddinShmemSpace(MAXALIGN(sizeof(GraphVersionState)));
+}
+
+void age_graph_version_shmem_startup(void)
+{
+ bool found;
+
+ LWLockAcquire(AddinShmemInitLock, LW_EXCLUSIVE);
+
+ shmem_version_state =
+ (GraphVersionState *) ShmemInitStruct("AGE Graph Version State",
+ sizeof(GraphVersionState),
+ &found);
+ if (!found)
+ {
+ LWLockInitialize(&shmem_version_state->lock,
+ LWLockNewTrancheId());
+ LWLockRegisterTranche(shmem_version_state->lock.tranche,
+ "age_graph_version");
+ shmem_version_state->num_entries = 0;
+ memset(shmem_version_state->entries, 0,
+ sizeof(shmem_version_state->entries));
+ }
+
+ LWLockRelease(AddinShmemInitLock);
+}
+#endif /* PG_VERSION_NUM < 170000 */
+
+/*
+ * Detect which version mode to use. Called once per backend on first access.
+ * Emits a DEBUG1 log message indicating the chosen mode.
+ */
+static void detect_version_mode(void)
+{
+#if PG_VERSION_NUM >= 170000
+ version_mode = VERSION_MODE_DSM;
+ elog(DEBUG1, "AGE: VLE cache using DSM version counter");
+#else
+ if (shmem_version_state != NULL)
+ {
+ version_mode = VERSION_MODE_SHMEM;
+ elog(DEBUG1, "AGE: VLE cache using SHMEM version counter");
+ }
+ else
+ {
+ version_mode = VERSION_MODE_SNAPSHOT;
+ elog(DEBUG1, "AGE: VLE cache using snapshot-based invalidation "
+ "(add AGE to shared_preload_libraries for better caching)");
+ }
+#endif
+}
+
+/*
+ * Get a pointer to the GraphVersionState, regardless of mode.
+ * Returns NULL only in SNAPSHOT mode (no shared memory available).
+ */
+static GraphVersionState *get_version_state(void)
+{
+ if (version_mode == VERSION_MODE_UNKNOWN)
+ detect_version_mode();
+
+#if PG_VERSION_NUM >= 170000
+ if (version_mode == VERSION_MODE_DSM)
+ return get_version_state_dsm();
+#endif
+
+ if (version_mode == VERSION_MODE_SHMEM)
+ return shmem_version_state;
+
+ return NULL;
+}
+
+/*
+ * Get the current version counter for a graph.
+ * Returns 0 if the graph has never been tracked or if shared memory
+ * is not available. Lock-free read via pg_atomic_read_u64.
+ */
+uint64 get_graph_version(Oid graph_oid)
+{
+ GraphVersionState *state = get_version_state();
+ int i;
+
+ if (state == NULL)
+ return 0;
+
+ /* lock-free scan of the array */
+ for (i = 0; i < state->num_entries; i++)
+ {
+ if (state->entries[i].graph_oid == graph_oid)
+ return pg_atomic_read_u64(&state->entries[i].version);
Review Comment:
missing braces
##########
src/backend/utils/adt/age_global_graph.c:
##########
@@ -1531,3 +1676,291 @@ Datum age_graph_stats(PG_FUNCTION_ARGS)
PG_RETURN_POINTER(agtype_value_to_agtype(result.res));
}
+
+/*
+ * ============================================================================
+ * Graph Version Counter Implementation
+ *
+ * Provides per-graph monotonic version counters in shared memory for
+ * cross-backend VLE cache invalidation. Three modes are supported:
+ *
+ * DSM (PG 17+): Uses GetNamedDSMSegment — works without shared_preload_libs
+ * SHMEM (PG <17): Uses shmem_request/startup hooks — needs shared_preload_libs
+ * SNAPSHOT: Falls back to original snapshot-based invalidation
+ * ============================================================================
+ */
+
+#if PG_VERSION_NUM >= 170000
+/*
+ * DSM path: GetNamedDSMSegment init callback.
+ * Called once when the DSM segment is first created.
+ */
+static void age_dsm_init_callback(void *ptr)
+{
+ GraphVersionState *state = (GraphVersionState *) ptr;
+
+ LWLockInitialize(&state->lock,
+ LWLockNewTrancheId());
+ LWLockRegisterTranche(state->lock.tranche, "age_graph_version");
+ state->num_entries = 0;
+ memset(state->entries, 0, sizeof(state->entries));
+}
+
+/*
+ * Get the shared GraphVersionState via DSM registry.
+ * The segment is created on first access and persists until server shutdown.
+ */
+static GraphVersionState *get_version_state_dsm(void)
+{
+ bool found;
+
+ return (GraphVersionState *)
+ GetNamedDSMSegment("age_graph_versions",
+ sizeof(GraphVersionState),
+ age_dsm_init_callback,
+ &found);
+}
+#endif /* PG_VERSION_NUM >= 170000 */
+
+/*
+ * SHMEM path: request and startup hooks for PG < 17.
+ * These are registered in _PG_init when shared_preload_libraries is used.
+ * On PG 17+, DSM is used instead and these functions are not called.
+ */
+#if PG_VERSION_NUM < 170000
+void age_graph_version_shmem_request(void)
+{
+ RequestAddinShmemSpace(MAXALIGN(sizeof(GraphVersionState)));
+}
+
+void age_graph_version_shmem_startup(void)
+{
+ bool found;
+
+ LWLockAcquire(AddinShmemInitLock, LW_EXCLUSIVE);
+
+ shmem_version_state =
+ (GraphVersionState *) ShmemInitStruct("AGE Graph Version State",
+ sizeof(GraphVersionState),
+ &found);
+ if (!found)
+ {
+ LWLockInitialize(&shmem_version_state->lock,
+ LWLockNewTrancheId());
+ LWLockRegisterTranche(shmem_version_state->lock.tranche,
+ "age_graph_version");
+ shmem_version_state->num_entries = 0;
+ memset(shmem_version_state->entries, 0,
+ sizeof(shmem_version_state->entries));
+ }
+
+ LWLockRelease(AddinShmemInitLock);
+}
+#endif /* PG_VERSION_NUM < 170000 */
+
+/*
+ * Detect which version mode to use. Called once per backend on first access.
+ * Emits a DEBUG1 log message indicating the chosen mode.
+ */
+static void detect_version_mode(void)
+{
+#if PG_VERSION_NUM >= 170000
+ version_mode = VERSION_MODE_DSM;
+ elog(DEBUG1, "AGE: VLE cache using DSM version counter");
+#else
+ if (shmem_version_state != NULL)
+ {
+ version_mode = VERSION_MODE_SHMEM;
+ elog(DEBUG1, "AGE: VLE cache using SHMEM version counter");
+ }
+ else
+ {
+ version_mode = VERSION_MODE_SNAPSHOT;
+ elog(DEBUG1, "AGE: VLE cache using snapshot-based invalidation "
+ "(add AGE to shared_preload_libraries for better caching)");
+ }
+#endif
+}
+
+/*
+ * Get a pointer to the GraphVersionState, regardless of mode.
+ * Returns NULL only in SNAPSHOT mode (no shared memory available).
+ */
+static GraphVersionState *get_version_state(void)
+{
+ if (version_mode == VERSION_MODE_UNKNOWN)
+ detect_version_mode();
+
+#if PG_VERSION_NUM >= 170000
+ if (version_mode == VERSION_MODE_DSM)
+ return get_version_state_dsm();
+#endif
+
+ if (version_mode == VERSION_MODE_SHMEM)
+ return shmem_version_state;
Review Comment:
missing braces
##########
src/backend/utils/adt/age_global_graph.c:
##########
@@ -1277,9 +1390,41 @@ Oid get_edge_entry_label_table_oid(edge_entry *ee)
return ee->edge_label_table_oid;
}
+/*
+ * Fetch edge properties on demand from the heap via stored TID.
+ * See get_vertex_entry_properties for memory and safety notes.
+ */
Datum get_edge_entry_properties(edge_entry *ee)
{
- return ee->edge_properties;
+ Relation rel;
+ HeapTupleData tuple;
+ Buffer buffer;
+ Datum result = (Datum) 0;
+
+ rel = table_open(ee->edge_label_table_oid, AccessShareLock);
+ tuple.t_self = ee->tid;
+
+ if (heap_fetch(rel, GetActiveSnapshot(), &tuple, &buffer, true))
+ {
+ TupleDesc tupdesc = RelationGetDescr(rel);
+ bool isnull;
+ Datum props;
+
+ /* properties is column 4 (1-indexed) */
+ props = heap_getattr(&tuple, 4, tupdesc, &isnull);
+ if (!isnull)
+ result = datumCopy(props, false, -1);
+
+ ReleaseBuffer(buffer);
+ }
+
+ table_close(rel, AccessShareLock);
+
+ if (result == (Datum) 0)
+ elog(ERROR, "get_edge_entry_properties: stale TID - "
Review Comment:
missing braces
##########
src/backend/utils/adt/age_global_graph.c:
##########
@@ -1531,3 +1676,291 @@ Datum age_graph_stats(PG_FUNCTION_ARGS)
PG_RETURN_POINTER(agtype_value_to_agtype(result.res));
}
+
+/*
+ * ============================================================================
+ * Graph Version Counter Implementation
+ *
+ * Provides per-graph monotonic version counters in shared memory for
+ * cross-backend VLE cache invalidation. Three modes are supported:
+ *
+ * DSM (PG 17+): Uses GetNamedDSMSegment — works without shared_preload_libs
+ * SHMEM (PG <17): Uses shmem_request/startup hooks — needs shared_preload_libs
+ * SNAPSHOT: Falls back to original snapshot-based invalidation
+ * ============================================================================
+ */
+
+#if PG_VERSION_NUM >= 170000
+/*
+ * DSM path: GetNamedDSMSegment init callback.
+ * Called once when the DSM segment is first created.
+ */
+static void age_dsm_init_callback(void *ptr)
+{
+ GraphVersionState *state = (GraphVersionState *) ptr;
+
+ LWLockInitialize(&state->lock,
+ LWLockNewTrancheId());
+ LWLockRegisterTranche(state->lock.tranche, "age_graph_version");
+ state->num_entries = 0;
+ memset(state->entries, 0, sizeof(state->entries));
+}
+
+/*
+ * Get the shared GraphVersionState via DSM registry.
+ * The segment is created on first access and persists until server shutdown.
+ */
+static GraphVersionState *get_version_state_dsm(void)
+{
+ bool found;
+
+ return (GraphVersionState *)
+ GetNamedDSMSegment("age_graph_versions",
+ sizeof(GraphVersionState),
+ age_dsm_init_callback,
+ &found);
+}
+#endif /* PG_VERSION_NUM >= 170000 */
+
+/*
+ * SHMEM path: request and startup hooks for PG < 17.
+ * These are registered in _PG_init when shared_preload_libraries is used.
+ * On PG 17+, DSM is used instead and these functions are not called.
+ */
+#if PG_VERSION_NUM < 170000
+void age_graph_version_shmem_request(void)
+{
+ RequestAddinShmemSpace(MAXALIGN(sizeof(GraphVersionState)));
+}
+
+void age_graph_version_shmem_startup(void)
+{
+ bool found;
+
+ LWLockAcquire(AddinShmemInitLock, LW_EXCLUSIVE);
+
+ shmem_version_state =
+ (GraphVersionState *) ShmemInitStruct("AGE Graph Version State",
+ sizeof(GraphVersionState),
+ &found);
+ if (!found)
+ {
+ LWLockInitialize(&shmem_version_state->lock,
+ LWLockNewTrancheId());
+ LWLockRegisterTranche(shmem_version_state->lock.tranche,
+ "age_graph_version");
+ shmem_version_state->num_entries = 0;
+ memset(shmem_version_state->entries, 0,
+ sizeof(shmem_version_state->entries));
+ }
+
+ LWLockRelease(AddinShmemInitLock);
+}
+#endif /* PG_VERSION_NUM < 170000 */
+
+/*
+ * Detect which version mode to use. Called once per backend on first access.
+ * Emits a DEBUG1 log message indicating the chosen mode.
+ */
+static void detect_version_mode(void)
+{
+#if PG_VERSION_NUM >= 170000
+ version_mode = VERSION_MODE_DSM;
+ elog(DEBUG1, "AGE: VLE cache using DSM version counter");
+#else
+ if (shmem_version_state != NULL)
+ {
+ version_mode = VERSION_MODE_SHMEM;
+ elog(DEBUG1, "AGE: VLE cache using SHMEM version counter");
+ }
+ else
+ {
+ version_mode = VERSION_MODE_SNAPSHOT;
+ elog(DEBUG1, "AGE: VLE cache using snapshot-based invalidation "
+ "(add AGE to shared_preload_libraries for better caching)");
+ }
+#endif
+}
+
+/*
+ * Get a pointer to the GraphVersionState, regardless of mode.
+ * Returns NULL only in SNAPSHOT mode (no shared memory available).
+ */
+static GraphVersionState *get_version_state(void)
+{
+ if (version_mode == VERSION_MODE_UNKNOWN)
+ detect_version_mode();
+
+#if PG_VERSION_NUM >= 170000
+ if (version_mode == VERSION_MODE_DSM)
+ return get_version_state_dsm();
+#endif
+
+ if (version_mode == VERSION_MODE_SHMEM)
+ return shmem_version_state;
+
+ return NULL;
+}
+
+/*
+ * Get the current version counter for a graph.
+ * Returns 0 if the graph has never been tracked or if shared memory
+ * is not available. Lock-free read via pg_atomic_read_u64.
+ */
+uint64 get_graph_version(Oid graph_oid)
+{
+ GraphVersionState *state = get_version_state();
+ int i;
+
+ if (state == NULL)
+ return 0;
Review Comment:
missing braces
##########
src/backend/utils/adt/age_global_graph.c:
##########
@@ -1531,3 +1676,291 @@ Datum age_graph_stats(PG_FUNCTION_ARGS)
PG_RETURN_POINTER(agtype_value_to_agtype(result.res));
}
+
+/*
+ * ============================================================================
+ * Graph Version Counter Implementation
+ *
+ * Provides per-graph monotonic version counters in shared memory for
+ * cross-backend VLE cache invalidation. Three modes are supported:
+ *
+ * DSM (PG 17+): Uses GetNamedDSMSegment — works without shared_preload_libs
+ * SHMEM (PG <17): Uses shmem_request/startup hooks — needs shared_preload_libs
+ * SNAPSHOT: Falls back to original snapshot-based invalidation
+ * ============================================================================
+ */
+
+#if PG_VERSION_NUM >= 170000
+/*
+ * DSM path: GetNamedDSMSegment init callback.
+ * Called once when the DSM segment is first created.
+ */
+static void age_dsm_init_callback(void *ptr)
+{
+ GraphVersionState *state = (GraphVersionState *) ptr;
+
+ LWLockInitialize(&state->lock,
+ LWLockNewTrancheId());
+ LWLockRegisterTranche(state->lock.tranche, "age_graph_version");
+ state->num_entries = 0;
+ memset(state->entries, 0, sizeof(state->entries));
+}
+
+/*
+ * Get the shared GraphVersionState via DSM registry.
+ * The segment is created on first access and persists until server shutdown.
+ */
+static GraphVersionState *get_version_state_dsm(void)
+{
+ bool found;
+
+ return (GraphVersionState *)
+ GetNamedDSMSegment("age_graph_versions",
+ sizeof(GraphVersionState),
+ age_dsm_init_callback,
+ &found);
+}
+#endif /* PG_VERSION_NUM >= 170000 */
+
+/*
+ * SHMEM path: request and startup hooks for PG < 17.
+ * These are registered in _PG_init when shared_preload_libraries is used.
+ * On PG 17+, DSM is used instead and these functions are not called.
+ */
+#if PG_VERSION_NUM < 170000
+void age_graph_version_shmem_request(void)
+{
+ RequestAddinShmemSpace(MAXALIGN(sizeof(GraphVersionState)));
+}
+
+void age_graph_version_shmem_startup(void)
+{
+ bool found;
+
+ LWLockAcquire(AddinShmemInitLock, LW_EXCLUSIVE);
+
+ shmem_version_state =
+ (GraphVersionState *) ShmemInitStruct("AGE Graph Version State",
+ sizeof(GraphVersionState),
+ &found);
+ if (!found)
+ {
+ LWLockInitialize(&shmem_version_state->lock,
+ LWLockNewTrancheId());
+ LWLockRegisterTranche(shmem_version_state->lock.tranche,
+ "age_graph_version");
+ shmem_version_state->num_entries = 0;
+ memset(shmem_version_state->entries, 0,
+ sizeof(shmem_version_state->entries));
+ }
+
+ LWLockRelease(AddinShmemInitLock);
+}
+#endif /* PG_VERSION_NUM < 170000 */
+
+/*
+ * Detect which version mode to use. Called once per backend on first access.
+ * Emits a DEBUG1 log message indicating the chosen mode.
+ */
+static void detect_version_mode(void)
+{
+#if PG_VERSION_NUM >= 170000
+ version_mode = VERSION_MODE_DSM;
+ elog(DEBUG1, "AGE: VLE cache using DSM version counter");
+#else
+ if (shmem_version_state != NULL)
+ {
+ version_mode = VERSION_MODE_SHMEM;
+ elog(DEBUG1, "AGE: VLE cache using SHMEM version counter");
+ }
+ else
+ {
+ version_mode = VERSION_MODE_SNAPSHOT;
+ elog(DEBUG1, "AGE: VLE cache using snapshot-based invalidation "
+ "(add AGE to shared_preload_libraries for better caching)");
+ }
+#endif
+}
+
+/*
+ * Get a pointer to the GraphVersionState, regardless of mode.
+ * Returns NULL only in SNAPSHOT mode (no shared memory available).
+ */
+static GraphVersionState *get_version_state(void)
+{
+ if (version_mode == VERSION_MODE_UNKNOWN)
+ detect_version_mode();
+
+#if PG_VERSION_NUM >= 170000
+ if (version_mode == VERSION_MODE_DSM)
Review Comment:
we do not use version macros
##########
src/backend/utils/adt/age_global_graph.c:
##########
@@ -1277,9 +1390,41 @@ Oid get_edge_entry_label_table_oid(edge_entry *ee)
return ee->edge_label_table_oid;
}
+/*
+ * Fetch edge properties on demand from the heap via stored TID.
+ * See get_vertex_entry_properties for memory and safety notes.
+ */
Datum get_edge_entry_properties(edge_entry *ee)
{
- return ee->edge_properties;
+ Relation rel;
+ HeapTupleData tuple;
+ Buffer buffer;
+ Datum result = (Datum) 0;
+
+ rel = table_open(ee->edge_label_table_oid, AccessShareLock);
+ tuple.t_self = ee->tid;
+
+ if (heap_fetch(rel, GetActiveSnapshot(), &tuple, &buffer, true))
+ {
+ TupleDesc tupdesc = RelationGetDescr(rel);
+ bool isnull;
+ Datum props;
+
+ /* properties is column 4 (1-indexed) */
+ props = heap_getattr(&tuple, 4, tupdesc, &isnull);
+ if (!isnull)
+ result = datumCopy(props, false, -1);
Review Comment:
missing braces
##########
src/backend/utils/adt/age_global_graph.c:
##########
@@ -1261,9 +1328,55 @@ Oid get_vertex_entry_label_table_oid(vertex_entry *ve)
return ve->vertex_label_table_oid;
}
+/*
+ * Fetch vertex properties on demand from the heap via stored TID.
+ *
+ * Returns a datumCopy of the properties in the current memory context.
+ * The caller does not need to free the result explicitly — it will be
+ * freed when the memory context is reset (typically the SRF multi-call
+ * context for VLE, which is cleaned up when the SRF completes).
+ *
+ * If the tuple is no longer visible (e.g., concurrent mutation between
+ * cache build and fetch), the version counter should have invalidated
+ * the cache. If we get here with a stale TID, it indicates a bug in
+ * the invalidation logic.
+ */
Datum get_vertex_entry_properties(vertex_entry *ve)
{
- return ve->vertex_properties;
+ Relation rel;
+ HeapTupleData tuple;
+ Buffer buffer;
+ Datum result = (Datum) 0;
+
+ rel = table_open(ve->vertex_label_table_oid, AccessShareLock);
+ tuple.t_self = ve->tid;
+
+ if (heap_fetch(rel, GetActiveSnapshot(), &tuple, &buffer, true))
+ {
+ TupleDesc tupdesc = RelationGetDescr(rel);
+ bool isnull;
+ Datum props;
+
+ /* properties is column 2 (1-indexed) */
+ props = heap_getattr(&tuple, 2, tupdesc, &isnull);
+ if (!isnull)
+ result = datumCopy(props, false, -1);
+
+ ReleaseBuffer(buffer);
+ }
+
+ table_close(rel, AccessShareLock);
+
+ /*
+ * If heap_fetch failed, the tuple is no longer visible. This should
+ * not happen under normal operation because the version counter
+ * invalidates the cache when the graph is mutated.
+ */
+ if (result == (Datum) 0)
+ elog(ERROR, "get_vertex_entry_properties: stale TID - "
Review Comment:
missing braces
##########
src/backend/age.c:
##########
@@ -35,6 +58,15 @@ void _PG_init(void)
process_utility_hook_init();
post_parse_analyze_init();
define_config_params();
+
+#if PG_VERSION_NUM < 170000
+ /* Register shared memory hooks for graph version tracking.
Review Comment:
we do not use version macros
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