[FIX] spreadsheet: batch process spreadsheet_revision.commands

Some dbs have `spreadsheet_revision` records with over 10 millions characters
in `commands`. If the number of record is high, this leads to memory errors.
We use a named cursor so the fetching is done in postgres and data are
processed in smaller batches by the upgrade process.

Author: vval-odoo

src/util/spreadsheet/misc.py

@@ -1,10 +1,13 @@
-from .. import json
+from .. import json, pg
+
+BATCH_SIZE = 10
 
 
 def iter_commands(cr, like_all=(), like_any=()):
     if not (bool(like_all) ^ bool(like_any)):
         raise ValueError("Please specify `like_all` or `like_any`, not both")
-    cr.execute(
+    ncr = pg.named_cursor(cr, itersize=BATCH_SIZE)
+    ncr.execute(
         """
         SELECT id,
                commands
@@ -13,7 +16,7 @@ def iter_commands(cr, like_all=(), like_any=()):
         """.format("ALL" if like_all else "ANY"),
         [list(like_all or like_any)],
     )
-    for revision_id, data in cr.fetchall():
+    for revision_id, data in ncr:
         data_loaded = json.loads(data)
         if "commands" not in data_loaded:
             continue
@@ -27,6 +30,7 @@ def iter_commands(cr, like_all=(), like_any=()):
             cr.execute(
                 "UPDATE spreadsheet_revision SET commands=%s WHERE id=%s", [json.dumps(data_loaded), revision_id]
             )
+    ncr.close()
 
 
 def process_commands(cr, callback, *args, **kwargs):