fix: avoid full temporary table by bulking getFileIDsForLfns

src/DIRAC/TransformationSystem/DB/TransformationDB.py

@@ -30,6 +30,8 @@
 MAX_ERROR_COUNT = 10
 
 TMP_TABLE_JOIN_LIMIT = 100
+# Max number of LFNs in the memory table
+GET_FILE_ID_BULK_SIZE = 30_000
 #############################################################################
 
 
@@ -1324,27 +1326,36 @@ def __getFileIDsForLfns(self, lfns, connection=False):
 
         if not lfns:
             return ({}, {})
-        # Create temporary table for LFNs
-        sqlCmd = "CREATE TEMPORARY TABLE to_query_LFNs (LFN VARCHAR(255) NOT NULL, PRIMARY KEY (LFN)) ENGINE=MEMORY;"
-        returnValueOrRaise(self._update(sqlCmd, conn=connection))
 
-        try:
-            # Insert LFNs into temporary table
-            sqlCmd = "INSERT INTO to_query_LFNs (LFN) VALUES ( %s )"
-            returnValueOrRaise(self._updatemany(sqlCmd, [(lfn,) for lfn in lfns], conn=connection))
+        lfns_to_ids = {}
+        ids_to_lfns = {}
 
-            # Query using JOIN with temporary table
-            req = "SELECT df.LFN, df.FileID FROM DataFiles df JOIN to_query_LFNs t ON df.LFN = t.LFN;"
-            res = returnValueOrRaise(self._query(req, conn=connection))
+        for lfn_bulk in breakListIntoChunks(lfns, GET_FILE_ID_BULK_SIZE):
+            # Create temporary table for LFNs
+            sqlCmd = (
+                "CREATE TEMPORARY TABLE to_query_LFNs (LFN VARCHAR(255) NOT NULL, PRIMARY KEY (LFN)) ENGINE=MEMORY;"
+            )
+            returnValueOrRaise(self._update(sqlCmd, conn=connection))
 
-            lfns = dict(res)
-            # Reverse dictionary
-            fids = {fileID: lfn for lfn, fileID in lfns.items()}
-            return (fids, lfns)
-        finally:
-            # Clean up temporary table
-            sqlCmd = "DROP TEMPORARY TABLE to_query_LFNs"
-            self._update(sqlCmd, conn=connection)
+            try:
+                # Insert LFNs into temporary table
+                sqlCmd = "INSERT INTO to_query_LFNs (LFN) VALUES ( %s )"
+                returnValueOrRaise(self._updatemany(sqlCmd, [(lfn,) for lfn in lfn_bulk], conn=connection))
+
+                # Query using JOIN with temporary table
+                req = "SELECT df.LFN, df.FileID FROM DataFiles df JOIN to_query_LFNs t ON df.LFN = t.LFN;"
+                res = returnValueOrRaise(self._query(req, conn=connection))
+
+                lfns_to_ids.update(res)
+                # Reverse dictionary
+
+            finally:
+                # Clean up temporary table
+                sqlCmd = "DROP TEMPORARY TABLE to_query_LFNs"
+                self._update(sqlCmd, conn=connection)
+
+        ids_to_lfns = {fileID: lfn for lfn, fileID in lfns_to_ids.items()}
+        return (ids_to_lfns, lfns_to_ids)
 
     def __getLfnsForFileIDs(self, fileIDs, connection=False):
         """Get lfns for the given list of fileIDs"""