include/sql/exchange_do_create_tables.sql

@@ -0,0 +1,193 @@
+--
+-- This file is part of TALER
+-- Copyright (C) 2014--2022 Taler Systems SA
+--
+-- TALER is free software; you can redistribute it and/or modify it under the
+-- terms of the GNU General Public License as published by the Free Software
+-- Foundation; either version 3, or (at your option) any later version.
+--
+-- TALER is distributed in the hope that it will be useful, but WITHOUT ANY
+-- WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+-- A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+--
+-- You should have received a copy of the GNU General Public License along with
+-- TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+--
+
+---------------------------------------------------------------------------
+--                   Main DB setup loop
+---------------------------------------------------------------------------
+
+
+CREATE OR REPLACE FUNCTION exchange_do_create_tables(
+  num_partitions INTEGER
+-- NULL: no partitions, add foreign constraints
+-- 0: no partitions, no foreign constraints
+-- 1: only 1 default partition
+-- > 1: normal partitions
+)
+  RETURNS VOID
+  LANGUAGE plpgsql
+AS $$
+DECLARE
+  tc CURSOR FOR
+    SELECT table_serial_id
+          ,name
+          ,action
+          ,partitioned
+          ,by_range
+      FROM exchange.exchange_tables
+     WHERE NOT finished
+     ORDER BY table_serial_id ASC;
+BEGIN
+  FOR rec IN tc
+  LOOP
+    CASE rec.action
+    -- "create" actions apply to master and partitions, providing the partition ID to the creation function (if any)
+    WHEN 'create'
+    THEN
+      IF (rec.partitioned AND
+          (num_partitions IS NOT NULL))
+      THEN
+        -- Create master table with partitioning.
+        EXECUTE FORMAT(
+          'SELECT exchange.create_table_%s (%s)'::text
+          ,rec.name
+          ,quote_literal('0')
+        );
+        IF (rec.by_range OR
+            (num_partitions = 0))
+        THEN
+          -- Create default partition.
+          IF (rec.by_range)
+          THEN
+            -- Range partition
+            EXECUTE FORMAT(
+              'CREATE TABLE exchange.%s_default'
+              ' PARTITION OF %s'
+              ' DEFAULT'
+             ,rec.name
+             ,rec.name
+            );
+          ELSE
+            -- Hash partition
+            EXECUTE FORMAT(
+              'CREATE TABLE exchange.%s_default'
+              ' PARTITION OF %s'
+              ' FOR VALUES WITH (MODULUS 1, REMAINDER 0)'
+             ,rec.name
+             ,rec.name
+            );
+          END IF;
+        ELSE
+          FOR i IN 1..num_partitions LOOP
+            -- Create num_partitions
+            EXECUTE FORMAT(
+               'CREATE TABLE exchange.%I'
+               ' PARTITION OF %I'
+               ' FOR VALUES WITH (MODULUS %s, REMAINDER %s)'
+              ,rec.name || '_' || i
+              ,rec.name
+              ,num_partitions
+              ,i-1
+            );
+          END LOOP;
+        END IF;
+      ELSE
+        -- Only create master table. No partitions.
+        EXECUTE FORMAT(
+          'SELECT exchange.create_table_%s ()'::text
+          ,rec.name
+        );
+      END IF;
+      EXECUTE FORMAT(
+        'DROP FUNCTION exchange.create_table_%s'::text
+          ,rec.name
+        );
+    -- "alter" actions apply to master and partitions (but are called without partition ID, as altering master applies to partitions for these); use when changing table layouts (adding or removing columns).
+    WHEN 'alter'
+    THEN
+      -- Alter master table.
+      EXECUTE FORMAT(
+        'SELECT exchange.alter_table_%s ()'::text
+        ,rec.name
+      );
+      EXECUTE FORMAT(
+        'DROP FUNCTION exchange.alter_table_%s'::text
+          ,rec.name
+        );
+    -- Constrain action apply to master OR each partition (but not on master if we have partitions); use to create (or remove) indices or constraints that apply to a partition and may not be aligned with the partition key
+    WHEN 'constrain'
+    THEN
+      ASSERT rec.partitioned, 'constrain action only applies to partitioned tables';
+      IF (num_partitions IS NULL)
+      THEN
+        -- Constrain master table
+        EXECUTE FORMAT(
+           'SELECT exchange.constrain_table_%s (NULL)'::text
+          ,rec.name
+        );
+      ELSE
+        IF ( (num_partitions = 0) OR
+             (rec.by_range) )
+        THEN
+          -- Constrain default table
+          EXECUTE FORMAT(
+             'SELECT exchange.constrain_table_%s (%s)'::text
+            ,rec.name
+            ,quote_literal('default')
+          );
+        ELSE
+          -- Constrain each partition
+          FOR i IN 1..num_partitions LOOP
+            EXECUTE FORMAT(
+              'SELECT exchange.constrain_table_%s (%s)'::text
+              ,rec.name
+              ,quote_literal(i)
+            );
+          END LOOP;
+        END IF;
+      END IF;
+      EXECUTE FORMAT(
+        'DROP FUNCTION exchange.constrain_table_%s'::text
+          ,rec.name
+        );
+    -- Foreign actions only apply if partitioning is off; use for foreign-key constraints that may span partitions
+    WHEN 'foreign'
+    THEN
+      IF (num_partitions IS NULL)
+      THEN
+        -- Add foreign constraints
+        EXECUTE FORMAT(
+          'SELECT exchange.foreign_table_%s (%s)'::text
+          ,rec.name
+          ,NULL
+        );
+      END IF;
+      EXECUTE FORMAT(
+        'DROP FUNCTION exchange.foreign_table_%s'::text
+          ,rec.name
+        );
+    -- "master" actions only apply to the master table
+    WHEN 'master'
+    THEN
+      EXECUTE FORMAT(
+        'SELECT exchange.master_table_%s ()'::text
+        ,rec.name
+      );
+      EXECUTE FORMAT(
+        'DROP FUNCTION exchange.master_table_%s'::text
+          ,rec.name
+        );
+    ELSE
+      ASSERT FALSE, 'unsupported action type: ' || rec.action;
+    END CASE;  -- END CASE (rec.action)
+    -- Mark as finished
+    UPDATE exchange.exchange_tables
+       SET finished=TRUE
+     WHERE table_serial_id=rec.table_serial_id;
+  END LOOP; -- create/alter/drop actions
+END $$;
+
+COMMENT ON FUNCTION exchange_do_create_tables
+  IS 'Creates all tables for the given number of partitions that need creating. Does NOT support sharding.';