Fix overlapping index checking (#117)

* Fix overlapping index checking

- Ensure we check only overlap on the current table
- Exclude local indexes
- Make sure PK are not taken into account

* Simplify tablename passing

src/Database/PostgreSQL/PQTypes/Checks.hs

@@ -508,7 +508,7 @@ checkDBStructure options tables = fmap mconcat . forM tables $ \(table, version)
       runQuery_ $ sqlGetForeignKeys table
       fkeys <- fetchMany fetchForeignKey
       triggers <- getDBTriggers tblName
-      checkedOverlaps <- checkOverlappingIndexes
+      checkedOverlaps <- checkOverlappingIndexes tblName
       return $
         mconcat
           [ checkColumns 1 tblColumns desc
@@ -714,8 +714,8 @@ checkDBStructure options tables = fmap mconcat . forM tables $ \(table, version)
                      \expected output into source code.)"
                    ]
 
-        checkOverlappingIndexes :: MonadDB m => m ValidationResult
-        checkOverlappingIndexes =
+        checkOverlappingIndexes :: MonadDB m => RawSQL () -> m ValidationResult
+        checkOverlappingIndexes tableName =
           if eoCheckOverlappingIndexes options
             then go
             else pure mempty
@@ -728,7 +728,7 @@ checkDBStructure options tables = fmap mconcat . forM tables $ \(table, version)
                       , " contains index "
                       , contained
                       ]
-              runSQL_ checkOverlappingIndexesQuery
+              runSQL_ $ checkOverlappingIndexesQuery tableName
               overlaps <- fetchMany handleOverlap
               pure $
                 if null overlaps

src/Database/PostgreSQL/PQTypes/Checks/Util.hs

@@ -190,8 +190,8 @@ objectHasMore otype ptype extra =
 arrListTable :: RawSQL () -> Text
 arrListTable tableName = " ->" <+> unRawSQL tableName <> ": "
 
-checkOverlappingIndexesQuery :: SQL
-checkOverlappingIndexesQuery =
+checkOverlappingIndexesQuery :: RawSQL () -> SQL
+checkOverlappingIndexesQuery tableName =
   smconcat
     [ "WITH"
     , -- get predicates (WHERE clause) definition in text format (ugly but the parsed version
@@ -201,7 +201,8 @@ checkOverlappingIndexesQuery =
     , "                         , ((regexp_match(pg_get_indexdef(indexrelid)"
     , "                                        , 'WHERE (.*)$')))[1] AS preddef"
     , "                    FROM pg_index"
-    , "                    WHERE indexprs IS NULL)"
+    , "                    WHERE indexprs IS NULL"
+    , "                    AND indrelid = '" <> raw tableName <> "'::regclass)"
     , -- add the rest of metadata and do the join
       "   , indexdata2 AS (SELECT t1.*"
     , "                         , pg_get_indexdef(t1.indexrelid) AS contained"
@@ -218,13 +219,19 @@ checkOverlappingIndexesQuery =
     , "  SELECT contained"
     , "       , contains"
     , "  FROM indexdata2"
+    , " JOIN pg_class c ON (c.oid = indexdata2.indexrelid)"
     , -- The indexes are the same or the "other" is larger than us
       "  WHERE (colotherindex = colindex"
     , "      OR colotherindex LIKE colindex || '+%')"
+    , -- and this is not a local index
+      "    AND NOT c.relname ILIKE 'local_%'"
     , -- and we have the same predicate
       "    AND other_preddef IS NOT DISTINCT FROM preddef"
     , -- and either the other is unique (so better than us) or none of us is unique
-      "    AND (other_indisunique"
-    , "      OR (NOT other_indisunique"
-    , "      AND NOT indisunique));"
+      "    AND (NOT indisunique)"
+    , "    OR ("
+    , "             indisunique"
+    , "         AND other_indisunique"
+    , "         AND colindex = colotherindex"
+    , ");"
     ]

test/Main.hs

@@ -2166,7 +2166,18 @@ overlapingIndexesTests connSource = do
   testCaseSteps' "Overlapping indexes tests" connSource $ \step -> do
     freshTestDB step
 
-    step "Check that overlapping indexes get flagged"
+    step "Migration is correct if not checking for overlapping indexes"
+    do
+      let options = defaultExtrasOptions {eoCheckOverlappingIndexes = False}
+      migrateDatabase
+        options
+        ["pgcrypto"]
+        []
+        []
+        [table1]
+        [createTableMigration table1]
+
+    step "Migration invalid when flagging overlapping indexes"
     do
       let options = defaultExtrasOptions {eoCheckOverlappingIndexes = True}
       assertException "Some indexes are overlapping" $
@@ -2181,7 +2192,7 @@ overlapingIndexesTests connSource = do
     table1 :: Table
     table1 =
       tblTable
-        { tblName = "idxTest"
+        { tblName = "idx_test"
         , tblVersion = 1
         , tblColumns =
             [ tblColumn {colName = "id", colType = UuidT, colNullable = False}