diff --git a/sql/upgrades/015.sql b/sql/upgrades/015.sql
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+++ b/sql/upgrades/015.sql
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+-- SWH DB schema upgrade
+-- from_version: 14
+-- to_version: 15
+-- description: merge directory_list_* tables into directory
+
+alter table directory
+    add column dir_entries  bigint[],
+    add column file_entries bigint[],
+    add column rev_entries  bigint[];
+
+with ls as (
+    -- we need an explicit sub-query here, because left joins aren't allowed in
+    -- update from_list
+    select id,
+           ls_d.entry_ids as dir_entries,
+	   ls_f.entry_ids as file_entries,
+	   ls_r.entry_ids as rev_entries
+    from directory as d
+    left join directory_list_dir  as ls_d on ls_d.dir_id = d.id
+    left join directory_list_file as ls_f on ls_f.dir_id = d.id
+    left join directory_list_rev  as ls_r on ls_r.dir_id = d.id
+)
+update directory
+    set dir_entries =  ls.dir_entries,
+        file_entries = ls.file_entries,
+	rev_entries =  ls.rev_entries
+    from ls
+    where ls.id = directory.id;
+
+create index on directory using gin (dir_entries);
+create index on directory using gin (file_entries);
+create index on directory using gin (rev_entries);
+
+drop table directory_list_dir;
+drop table directory_list_file;
+drop table directory_list_rev;