Fix issue creating dimensional constraints

During chunk creation, the chunk's dimensional CHECK constraints are created via an "upcall" to PL/pgSQL code. However, creating dimensional constraints in PL/pgSQL code sometimes fails, especially during high-concurrency inserts, because PL/pgSQL code scans metadata using a snapshot that might not see the same metadata as the C code. As a result, chunk creation sometimes fail during constraint creation. To fix this issue, implement dimensional CHECK-constraint creation in C code. Other constraints (FK, PK, etc.) are still created via an upcall, but should probably also be rewritten in C. However, since these constraints don't depend on recently updated metadata, this is left to a future change. Fixes #5456
timescale · Mar 23, 2023 · 2105a06 · 2105a06
1 parent 72c0f5b
commit 2105a06
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Showing 14 changed files with 412 additions and 215 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -24,6 +24,7 @@ accidentally triggering the load of a previous DB version.**
 * #5442 Decompression may have lost DEFAULT values
 * #5446 Add checks for malloc failure in libpq calls
 * #5470 Ensure superuser perms during copy/move chunk
+* #5459 Fix issue creating dimensional constraints
 
 **Thanks**
 * @nikolaps for reporting an issue with the COPY fetcher

diff --git a/sql/chunk_constraint.sql b/sql/chunk_constraint.sql
@@ -22,12 +22,7 @@ BEGIN
     SELECT * INTO STRICT hypertable_row FROM _timescaledb_catalog.hypertable h WHERE h.id = chunk_row.hypertable_id;
 
     IF chunk_constraint_row.dimension_slice_id IS NOT NULL THEN
-        check_sql = _timescaledb_internal.dimension_slice_get_constraint_sql(chunk_constraint_row.dimension_slice_id);
-        IF check_sql IS NOT NULL THEN
-            def := format('CHECK (%s)',  check_sql);
-        ELSE
-            def := NULL;
-        END IF;
+	    RAISE 'cannot create dimension constraint %', chunk_constraint_row;
     ELSIF chunk_constraint_row.hypertable_constraint_name IS NOT NULL THEN
 
         SELECT oid, contype INTO STRICT constraint_oid, constraint_type FROM pg_constraint

diff --git a/sql/size_utils.sql b/sql/size_utils.sql
@@ -366,7 +366,8 @@ CREATE OR REPLACE FUNCTION _timescaledb_internal.range_value_to_pretty(
 $BODY$
 DECLARE
 BEGIN
-    IF NOT _timescaledb_internal.dimension_is_finite(time_value) THEN
+    IF NOT (time_value > (-9223372036854775808)::bigint AND
+	   	    time_value < 9223372036854775807::bigint) THEN
         RETURN '';
     END IF;
     IF time_value IS NULL THEN

diff --git a/sql/updates/latest-dev.sql b/sql/updates/latest-dev.sql
@@ -21,3 +21,6 @@ CREATE FUNCTION _timescaledb_internal.recompress_chunk_segmentwise(REGCLASS, BOO
 AS '@MODULE_PATHNAME@', 'ts_recompress_chunk_segmentwise' LANGUAGE C STRICT VOLATILE;
 CREATE FUNCTION _timescaledb_internal.get_compressed_chunk_index_for_recompression(REGCLASS) RETURNS REGCLASS
 AS '@MODULE_PATHNAME@', 'ts_get_compressed_chunk_index_for_recompression' LANGUAGE C STRICT VOLATILE;
+
+DROP FUNCTION _timescaledb_internal.dimension_is_finite;
+DROP FUNCTION _timescaledb_internal.dimension_slice_get_constraint_sql;
diff --git a/sql/updates/reverse-dev.sql b/sql/updates/reverse-dev.sql
@@ -12,3 +12,90 @@ DROP TABLE IF EXISTS _timescaledb_catalog.continuous_aggs_watermark;
 DROP FUNCTION IF EXISTS _timescaledb_internal.cagg_watermark_materialized(hypertable_id INTEGER);
 DROP FUNCTION _timescaledb_internal.recompress_chunk_segmentwise(REGCLASS, BOOLEAN);
 DROP FUNCTION _timescaledb_internal.get_compressed_chunk_index_for_recompression(REGCLASS);
+
+CREATE OR REPLACE FUNCTION _timescaledb_internal.dimension_is_finite(
+    val      BIGINT
+)
+    RETURNS BOOLEAN LANGUAGE SQL IMMUTABLE PARALLEL SAFE AS
+$BODY$
+    --end values of bigint reserved for infinite
+    SELECT val > (-9223372036854775808)::bigint AND val < 9223372036854775807::bigint
+$BODY$ SET search_path TO pg_catalog, pg_temp;
+
+CREATE OR REPLACE FUNCTION _timescaledb_internal.dimension_slice_get_constraint_sql(
+    dimension_slice_id  INTEGER
+)
+    RETURNS TEXT LANGUAGE PLPGSQL VOLATILE AS
+$BODY$
+DECLARE
+    dimension_slice_row _timescaledb_catalog.dimension_slice;
+    dimension_row _timescaledb_catalog.dimension;
+    dimension_def TEXT;
+    dimtype REGTYPE;
+    parts TEXT[];
+BEGIN
+    SELECT * INTO STRICT dimension_slice_row
+    FROM _timescaledb_catalog.dimension_slice
+    WHERE id = dimension_slice_id;
+
+    SELECT * INTO STRICT dimension_row
+    FROM _timescaledb_catalog.dimension
+    WHERE id = dimension_slice_row.dimension_id;
+
+    IF dimension_row.partitioning_func_schema IS NOT NULL AND
+       dimension_row.partitioning_func IS NOT NULL THEN
+        SELECT prorettype INTO STRICT dimtype
+        FROM pg_catalog.pg_proc pro
+        WHERE pro.oid = format('%I.%I', dimension_row.partitioning_func_schema, dimension_row.partitioning_func)::regproc::oid;
+
+        dimension_def := format('%1$I.%2$I(%3$I)',
+             dimension_row.partitioning_func_schema,
+             dimension_row.partitioning_func,
+             dimension_row.column_name);
+    ELSE
+        dimension_def := format('%1$I', dimension_row.column_name);
+        dimtype := dimension_row.column_type;
+    END IF;
+
+    IF dimension_row.num_slices IS NOT NULL THEN
+
+        IF  _timescaledb_internal.dimension_is_finite(dimension_slice_row.range_start) THEN
+            parts = parts || format(' %1$s >= %2$L ', dimension_def, dimension_slice_row.range_start);
+        END IF;
+
+        IF _timescaledb_internal.dimension_is_finite(dimension_slice_row.range_end) THEN
+            parts = parts || format(' %1$s < %2$L ', dimension_def, dimension_slice_row.range_end);
+        END IF;
+
+        IF array_length(parts, 1) = 0 THEN
+            RETURN NULL;
+        END IF;
+        return array_to_string(parts, 'AND');
+    ELSE
+        -- only works with time for now
+        IF _timescaledb_internal.time_literal_sql(dimension_slice_row.range_start, dimtype) =
+           _timescaledb_internal.time_literal_sql(dimension_slice_row.range_end, dimtype) THEN
+            RAISE 'time-based constraints have the same start and end values for column "%": %',
+                    dimension_row.column_name,
+                    _timescaledb_internal.time_literal_sql(dimension_slice_row.range_end, dimtype);
+        END IF;
+
+        parts = ARRAY[]::text[];
+
+        IF _timescaledb_internal.dimension_is_finite(dimension_slice_row.range_start) THEN
+            parts = parts || format(' %1$s >= %2$s ',
+            dimension_def,
+            _timescaledb_internal.time_literal_sql(dimension_slice_row.range_start, dimtype));
+        END IF;
+
+        IF _timescaledb_internal.dimension_is_finite(dimension_slice_row.range_end) THEN
+            parts = parts || format(' %1$s < %2$s ',
+            dimension_def,
+            _timescaledb_internal.time_literal_sql(dimension_slice_row.range_end, dimtype));
+        END IF;
+
+        return array_to_string(parts, 'AND');
+    END IF;
+END
+$BODY$ SET search_path TO pg_catalog, pg_temp;
+
diff --git a/sql/util_internal_table_ddl.sql b/sql/util_internal_table_ddl.sql
@@ -5,93 +5,6 @@
 -- This file contains functions associated with creating new
 -- hypertables.
 
-CREATE OR REPLACE FUNCTION _timescaledb_internal.dimension_is_finite(
-    val      BIGINT
-)
-    RETURNS BOOLEAN LANGUAGE SQL IMMUTABLE PARALLEL SAFE AS
-$BODY$
-    --end values of bigint reserved for infinite
-    SELECT val > (-9223372036854775808)::bigint AND val < 9223372036854775807::bigint
-$BODY$ SET search_path TO pg_catalog, pg_temp;
-
-
-CREATE OR REPLACE FUNCTION _timescaledb_internal.dimension_slice_get_constraint_sql(
-    dimension_slice_id  INTEGER
-)
-    RETURNS TEXT LANGUAGE PLPGSQL VOLATILE AS
-$BODY$
-DECLARE
-    dimension_slice_row _timescaledb_catalog.dimension_slice;
-    dimension_row _timescaledb_catalog.dimension;
-    dimension_def TEXT;
-    dimtype REGTYPE;
-    parts TEXT[];
-BEGIN
-    SELECT * INTO STRICT dimension_slice_row
-    FROM _timescaledb_catalog.dimension_slice
-    WHERE id = dimension_slice_id;
-
-    SELECT * INTO STRICT dimension_row
-    FROM _timescaledb_catalog.dimension
-    WHERE id = dimension_slice_row.dimension_id;
-
-    IF dimension_row.partitioning_func_schema IS NOT NULL AND
-       dimension_row.partitioning_func IS NOT NULL THEN
-        SELECT prorettype INTO STRICT dimtype
-        FROM pg_catalog.pg_proc pro
-        WHERE pro.oid = format('%I.%I', dimension_row.partitioning_func_schema, dimension_row.partitioning_func)::regproc::oid;
-
-        dimension_def := format('%1$I.%2$I(%3$I)',
-             dimension_row.partitioning_func_schema,
-             dimension_row.partitioning_func,
-             dimension_row.column_name);
-    ELSE
-        dimension_def := format('%1$I', dimension_row.column_name);
-        dimtype := dimension_row.column_type;
-    END IF;
-
-    IF dimension_row.num_slices IS NOT NULL THEN
-
-        IF  _timescaledb_internal.dimension_is_finite(dimension_slice_row.range_start) THEN
-            parts = parts || format(' %1$s >= %2$L ', dimension_def, dimension_slice_row.range_start);
-        END IF;
-
-        IF _timescaledb_internal.dimension_is_finite(dimension_slice_row.range_end) THEN
-            parts = parts || format(' %1$s < %2$L ', dimension_def, dimension_slice_row.range_end);
-        END IF;
-
-        IF array_length(parts, 1) = 0 THEN
-            RETURN NULL;
-        END IF;
-        return array_to_string(parts, 'AND');
-    ELSE
-        -- only works with time for now
-        IF _timescaledb_internal.time_literal_sql(dimension_slice_row.range_start, dimtype) =
-           _timescaledb_internal.time_literal_sql(dimension_slice_row.range_end, dimtype) THEN
-            RAISE 'time-based constraints have the same start and end values for column "%": %',
-                    dimension_row.column_name,
-                    _timescaledb_internal.time_literal_sql(dimension_slice_row.range_end, dimtype);
-        END IF;
-
-        parts = ARRAY[]::text[];
-
-        IF _timescaledb_internal.dimension_is_finite(dimension_slice_row.range_start) THEN
-            parts = parts || format(' %1$s >= %2$s ',
-            dimension_def,
-            _timescaledb_internal.time_literal_sql(dimension_slice_row.range_start, dimtype));
-        END IF;
-
-        IF _timescaledb_internal.dimension_is_finite(dimension_slice_row.range_end) THEN
-            parts = parts || format(' %1$s < %2$s ',
-            dimension_def,
-            _timescaledb_internal.time_literal_sql(dimension_slice_row.range_end, dimtype));
-        END IF;
-
-        return array_to_string(parts, 'AND');
-    END IF;
-END
-$BODY$ SET search_path TO pg_catalog, pg_temp;
-
 -- Outputs the create_hypertable command to recreate the given hypertable.
 --
 -- This is currently used internally for our single hypertable backup tool