Author: julianfoad
Date: Tue Jul 6 19:20:11 2010
New Revision: 960985
URL: http://svn.apache.org/viewvc?rev=960985&view=rev
Log:
* notes/wc-ng/single-db-per-wc
New file.
Added:
subversion/trunk/notes/wc-ng/single-db-per-wc
Added: subversion/trunk/notes/wc-ng/single-db-per-wc
URL:
http://svn.apache.org/viewvc/subversion/trunk/notes/wc-ng/single-db-per-wc?rev=960985&view=auto
==============================================================================
--- subversion/trunk/notes/wc-ng/single-db-per-wc (added)
+++ subversion/trunk/notes/wc-ng/single-db-per-wc Tue Jul 6 19:20:11 2010
@@ -0,0 +1,94 @@
+"Single DB" in this context means one SQLite DB in the root of each working
+copy.
+
+
+Build and Test
+==============
+
+To build with experimental single-DB support:
+ define SINGLE_DB ("CFLAGS=-DSINGLE_DB configure ...")
+ define SVN_WC__VERSION to 18 in wc.h
+
+Current test results (r960984):
+ most/all C tests pass
+ half of the Python tests fail; common errors are
+ Wrong results but no error message.
+ Error: columns wc_id, local_dir_relpath are not unique
+ Error: No write-lock in '...'
+ Crash.
+
+
+Upgrade: Migration of DB tables from subdir DBs to root DB
+==========================================================
+
+"Move into root's table" means move each row into the same table in the WC
+root's DB, and we expect no duplicates.
+
+"Merge into root's table" means we move the row into the root's table,
+unless a row that's identical apart from its id is already present, in which
+case we use the existing row's id.
+
+REPOSITORY
+
+ Merge into root's table, which may result in assigning new id's.
+ Change all repos id's accordingly in the other tables being migrated:
+ BASE_NODE.repos_id
+ WORKING_NODE.copyfrom_repos_id
+ LOCK.repos_id
+ # and in tree conflict info?
+
+ Note: I already have two repos id's in some parts of some of my svn
+ working copies, so this is not purely theoretical.
+
+WCROOT
+
+ Merge into root's table;
+ theoretically we should assign new id's and change them where they
+ appear in other tables, but in practice the id is always 1 so we can
+ just assert that.
+
+BASE_NODE
+
+ Move into root's table;
+ omit if .kind == subdir
+ change .local_relpath
+ set .parent_relpath
+
+WORKING_NODE
+
+ Move into root's table;
+ omit if .kind == subdir (?)
+ change .local_relpath
+ set .parent_relpath
+
+ACTUAL_NODE
+
+ Move into root's table;
+ change .local_relpath
+ set .parent_relpath
+
+LOCK
+
+ Move into root's table.
+
+PRISTINE
+
+ Move into root's table.
+ Move the corresponding pristine text files into root's 'pristine' dir.
+ Change root's pristine directory to sharded (or this could be a
+ separate upgrade).
+
+WC_LOCK
+
+ Move into root's table;
+ change .local_dir_relpath
+
+WORK_QUEUE
+
+ Ensure WORK_QUEUE is empty.
+
+
+Code Changes Required
+=====================
+
+
