WIP: phase 7: vorbereitung des partionings

patches/patch20200426-3.0.0/versioning.sql

@@ -34,6 +34,7 @@ CREATE TABLE entity_version (
   _iversion INT UNSIGNED NOT NULL,
   _ipparent INT UNSIGNED NULL,
   srid VARBINARY(255) NOT NULL,
+  _is_head BOOLEAN DEFAULT FALSE,
   PRIMARY KEY (`entity_id`, `_iversion`),
   FOREIGN KEY (`entity_id`) REFERENCES `entities` (`id`) ON DELETE CASCADE,
   FOREIGN KEY (`srid`) REFERENCES `transactions` (`srid`),

procedures/entityVersioning.sql

@@ -57,10 +57,18 @@ BEGIN
         SET newiversion = 1;
     END IF;
 
+    -- remove old HEAD marker
+    UPDATE entity_version
+        SET _is_head = FALSE
+        WHERE entity_id = EntityID
+        AND _is_head IS TRUE;
+
+
+    -- insert new version with HEAD marker
     INSERT INTO entity_version
-        (entity_id, hash, version, _iversion, _ipparent, srid)
+        (entity_id, hash, version, _iversion, _ipparent, srid, _is_head)
         VALUES
-        (EntityID, Hash, Version, newiversion, newipparent, Transaction);
+        (EntityID, Hash, Version, newiversion, newipparent, Transaction, TRUE);
 
 
 
@@ -121,10 +129,19 @@ CREATE FUNCTION db_2_0.get_head_version(
 RETURNS VARBINARY(255)
 READS SQL DATA
 BEGIN
-    RETURN get_head_relative(EntityID, 0);
+    RETURN (
+        SELECT e.version
+            FROM entity_version AS e
+            WHERE e.entity_id = EntityID
+            AND e._is_head IS TRUE
+        );
 END;
 //
 
+-- This implementation assumes that the distance from the head equals the
+-- difference between the _iversion numbers. This will not be correct anymore,
+-- as soon as branches may split and merge. Then, an tree-walk will be
+-- necessary, traversing the primary parents (_pparent), will be necessary.
 DROP FUNCTION IF EXISTS db_2_0.get_head_relative //
 CREATE FUNCTION db_2_0.get_head_relative(
     EntityID INT UNSIGNED,
@@ -156,6 +173,9 @@ BEGIN
         ON ( c.srid = t.srid )
         WHERE c.entity_id = EntityID
         AND c._ipparent is Null
+    -- TODO This first SELECT statement is necessary because the second one
+    -- does not return the root. However, this should be doable in one go with
+    -- a left join.
 
     -- retrieve branches
     UNION SELECT c.version AS child,

tests/test_autotap.sql

@@ -2216,7 +2216,7 @@ SELECT tap.table_collation_is('_caosdb_schema_unit_tests','entity_version','utf8
 SELECT tap.table_engine_is('_caosdb_schema_unit_tests','entity_version','InnoDB','');
 
 -- COLUMNS
-SELECT tap.columns_are('_caosdb_schema_unit_tests','entity_version','`entity_id`,`hash`,`version`,`_iversion`,`_ipparent`,`srid`','');
+SELECT tap.columns_are('_caosdb_schema_unit_tests','entity_version','`entity_id`,`hash`,`version`,`_iversion`,`_ipparent`,`srid`,`_is_head`','');
 
 -- COLUMN entity_version.entity_id
 
@@ -2272,6 +2272,15 @@ SELECT tap.col_default_is('_caosdb_schema_unit_tests','entity_version','srid',NU
 SELECT tap.col_charset_is('_caosdb_schema_unit_tests','entity_version','srid',NULL,'');
 SELECT tap.col_collation_is('_caosdb_schema_unit_tests','entity_version','srid',NULL,'');
 
+-- COLUMN entity_version._is_head
+
+SELECT tap.has_column('_caosdb_schema_unit_tests','entity_version','_is_head','');
+SELECT tap.col_column_type_is('_caosdb_schema_unit_tests','entity_version','_is_head','tinyint(1)','');
+SELECT tap.col_extra_is('_caosdb_schema_unit_tests','entity_version','_is_head','','');
+SELECT tap.col_default_is('_caosdb_schema_unit_tests','entity_version','_is_head','0','');
+SELECT tap.col_charset_is('_caosdb_schema_unit_tests','entity_version','_is_head',NULL,'');
+SELECT tap.col_collation_is('_caosdb_schema_unit_tests','entity_version','_is_head',NULL,'');
+
 -- CONSTRAINTS
 SELECT tap.constraints_are('_caosdb_schema_unit_tests','entity_version','`entity_id`,`PRIMARY`,`entity_version_ibfk_1`,`entity_version_ibfk_2`','');
 

tests/test_entity_versioning.sql

@@ -30,7 +30,7 @@ SELECT count(*) INTO @x FROM entity_version;
 SELECT tap.eq(@x, 0, "no versions there yet");
 
 CALL insert_single_child_version(@EntityID, "hashbla", "versionbla", NULL, "SRIDbla");
-SELECT _ipparent INTO @x from entity_version WHERE version="versionbla";
+SELECT _ipparent INTO @x from entity_version WHERE version="versionbla" AND _is_head IS TRUE;
 SELECT tap.eq(@x, NULL, "no parent for the first version");
 
 -- add a second version
@@ -38,10 +38,10 @@ SELECT count(*) INTO @x FROM entity_version;
 SELECT tap.eq(@x, 1, "one version there yet");
 CALL insert_single_child_version(@EntityID, "hashblub", "versionblub", "versionbla", "SRIDblub");
 
-SELECT _ipparent INTO @x from entity_version WHERE version="versionblub";
+SELECT _ipparent INTO @x from entity_version WHERE version="versionblub" AND _is_head IS TRUE;
 SELECT tap.eq(@x, 1, "the original entity is the parent");
 
--- error: parent does not exist
+-- test error: parent does not exist
 SELECT count(*) INTO @x FROM entity_version;
 SELECT tap.eq(@x, 2, "two version there yet");
 
@@ -89,10 +89,10 @@ CALL insertEntityProperty(0, @EntityID, 17, "null_data", NULL, NULL,
 
 SELECT count(*) INTO @x FROM entity_version WHERE entity_id = @EntityID;
 SELECT tap.eq(@x, 1, "after insertEntity, a version is there.");
-SELECT _iversion INTO @x FROM entity_version WHERE entity_id = @EntityID and _ipparent is NULL;
+SELECT _iversion INTO @x FROM entity_version WHERE entity_id = @EntityID and _ipparent is NULL AND _is_head IS TRUE;
 SELECT tap.eq(@x, 1, "after insertEntity, the _iversion number is 1.");
 
-SELECT _ipparent INTO @x from entity_version WHERE entity_id = @EntityID;
+SELECT _ipparent INTO @x from entity_version WHERE entity_id = @EntityID AND _is_head IS TRUE;
 SELECT tap.eq(@x, NULL, "no parent for the freshly inserted entity");
 SELECT tap.eq(count(*), 0, "no entity in archive_entities before first update")
     FROM archive_entities;
@@ -105,9 +105,9 @@ CALL updateEntity(@EntityID, "NewEntityName", "NewEntityDesc", "RECORD", NULL, N
 SELECT count(*) INTO @x FROM entity_version WHERE entity_id = @EntityID;
 SELECT tap.eq(@x, 2, "after updateEntity, a second version is there.");
 
-SELECT _iversion INTO @x FROM entity_version WHERE entity_id = @EntityID and _ipparent = 1;
+SELECT _iversion INTO @x FROM entity_version WHERE entity_id = @EntityID and _ipparent = 1 AND _is_head IS TRUE;
 SELECT tap.eq(@x, 2, "after updateEntity, the _iversion number incremented.");
-SELECT _ipparent INTO @x FROM entity_version WHERE entity_id = @EntityID and _ipparent = 1;
+SELECT _ipparent INTO @x FROM entity_version WHERE entity_id = @EntityID and _ipparent = 1 AND _is_head IS TRUE;
 SELECT tap.eq(@x, 1, "after updateEntity, the _pparent points to the first version");
 
 SELECT tap.eq(count(*), 1, "after updateEntity, one entity in archive_entities")
@@ -152,6 +152,12 @@ CALL updateEntity(@EntityID, "EntityName", "EntityDesc", "RECORDTYPE", NULL, NUL
 SELECT count(*) INTO @x FROM entity_version WHERE entity_id = @EntityID;
 SELECT tap.eq(@x, 3, "after 2nd updateEntity, a 3rd version is there.");
 
+SELECT tap.eq(count(*), 1, "after 2nd updateEntity, a single HEAD version is there.")
+    FROM entity_version WHERE entity_id = @EntityID AND _is_head IS TRUE;
+
+SELECT tap.eq(count(*), 2, "after 2nd updateEntity, two non-HEAD versions are there.")
+    FROM entity_version WHERE entity_id = @EntityID AND _is_head IS FALSE;
+
 SELECT _iversion INTO @x FROM entity_version WHERE entity_id = @EntityID and _ipparent = 2;
 SELECT tap.eq(@x, 3, "after 2nd updateEntity, the _iversion number incremented again.");
 SELECT _ipparent INTO @x FROM entity_version WHERE entity_id = @EntityID and _iversion = 3;