Florian Weimer <fwei...@bfk.de> writes:
> It seems an optimizer issue. Which version of SQLite do you use?
I was using 3.6.21-2~bpo50 on Debian/stable. I've just built a local
3.7.3-1 and get the same result.
The database has 377021 rows. The exact commands are:
sqlite3 wcx.db "select count(*) from nodes where wc_id = 1 and local_relpath
= 'zag1/zag27'"
sqlite3 wcx.db "select count(*) from nodes where wc_id = 1 and (local_relpath
> 'zig1/zag27/' and local_relpath < 'zig1/zag270')"
Which select 1 row and 100 rows and take 0.006s. The combined command
sqlite3 wcx.db "select count(*) from nodes where wc_id = 1 and local_relpath
= 'zig1/zag27' or (local_relpath > 'zig1/zag27/' and local_relpath <
'zig1/zag270')"
selects 101 rows and takes 0.35s.
The script to create the database is:
#!/usr/bin/python
import os, sqlite3
try: os.remove('wcx.db')
except: pass
c = sqlite3.connect('wcx.db')
c.execute("""pragma case_sensitive_like=1""")
c.execute("""pragma foreign_keys=on""")
c.execute("""pragma synchronous=off""")
c.execute("""create table repository (
id integer primary key autoincrement,
root text unique not null,
uuid text not null)""")
c.execute("""create index i_uuid on repository (uuid)""")
c.execute("""create index i_root on repository (root)""")
c.execute("""create table wcroot (
id integer primary key autoincrement,
local_abspath text unique)""")
c.execute("""create unique index i_local_abspath on wcroot (local_abspath)""")
c.execute("""create table nodes (
wc_id integer not null references wcroot (id),
local_relpath text not null,
op_depth integer not null,
parent_relpath text,
repos_id integer references repository (id),
repos_path text,
revision integer,
presence text not null,
depth text,
moved_here integer,
moved_to text,
kind text not null,
changed_revision integer,
changed_date integer,
changed_author text,
checksum text
properties blob,
translated_size integer,
last_mod_time integer,
dav_cache blob,
symlink_target text,
file_external text,
primary key(wc_id, local_relpath, op_depth))""")
c.execute("""create index i_parent on nodes (wc_id,
parent_relpath,
local_relpath, op_depth)""")
c.execute("""create table lock (
repos_id integer not null references repository (id),
repos_relpath text not null,
lock_token text not null,
lock_owner text,
lock_comment text,
lock_date integer,
primary key (repos_id, repos_relpath))""")
c.execute("""insert into repository (root, uuid) values (
"http://example.com/repo";,
"f738be9e-409d-481f-b246-1fb6a969aba2")""")
c.execute("""insert into wcroot(local_abspath) values ("/wc")""")
c.execute("""insert into nodes (
wc_id,
local_relpath,
op_depth,
repos_id,
repos_path,
parent_relpath,
presence,
kind)
values (
1,
"",
0,
1,
"trunk",
NULL,
"normal",
"dir")""")
for i in range(100):
c.execute("""insert into nodes (
wc_id,
local_relpath,
op_depth,
repos_id,
repos_path,
parent_relpath,
presence,
kind)
values (
1,
"foo"""+str(i)+"""",
0,
1,
"trunk/foo"""+str(i)+"""",
"",
"normal",
"file")""")
if i >= 60:
continue;
c.execute("""insert into nodes (
wc_id,
local_relpath,
op_depth,
repos_id,
repos_path,
parent_relpath,
presence,
kind)
values (
1,
"zag"""+str(i)+"""",
0,
1,
"trunk/zag"""+str(i)+"""",
"",
"normal",
"dir")""")
c.execute("""insert into nodes (
wc_id,
local_relpath,
op_depth,
repos_id,
repos_path,
parent_relpath,
presence,
kind)
values (
1,
"zig"""+str(i)+"""",
0,
1,
"trunk/zig"""+str(i)+"""",
"",
"normal",
"dir")""")
for j in range(100):
c.execute("""insert into nodes (
wc_id,
local_relpath,
op_depth,
repos_id,
repos_path,
parent_relpath,
presence,
kind)
values (
1,
"zag"""+str(i)+"/foo"+str(j)+"""",
0,
1,
"trunk/zag"""+str(i)+"/foo"+str(j)+"""",
"zag"""+str(i)+"""",
"normal",
"file")""")
if j % 10 == 1:
c.execute("""insert into nodes (
wc_id,
local_relpath,
op_depth,
repos_id,
repos_path,
parent_relpath,
presence,
kind)
values (
1,
"zag"""+str(i)+"/foo"+str(j)+"""",
3,
1,
"trunk/zag"""+str(i)+"/foo"+str(j)+"""",
"zag"""+str(i)+"""",
"base-delete",
"file")""")
c.execute("""insert into nodes (
wc_id,
local_relpath,
op_depth,
repos_id,
repos_path,
parent_relpath,
presence,
kind)
values (
1,
"zag"""+str(i)+"/bar"+str(j)+"""",
3,
null,
null,
"zag"""+str(i)+"""",
"normal",
"file")""")
c.execute("""insert into nodes (
wc_id,
local_relpath,
op_depth,
repos_id,
repos_path,
parent_relpath,
presence,
kind)
values (
1,
"zig"""+str(i)+"/foo"+str(j)+"""",
0,
1,
"trunk/zig"""+str(i)+"/foo"+str(j)+"""",
"zig"""+str(i)+"""",
"normal",
"file")""")
if j >= 60:
continue
c.execute("""insert into nodes (
wc_id,
local_relpath,
op_depth,
repos_id,
repos_path,
parent_relpath,
presence,
kind)
values (
1,
"zig"""+str(i)+"/zag"+str(j)+"""",
0,
1,
"trunk/zig"""+str(i)+"/zag"+str(j)+"""",
"zig"""+str(i)+"""",
"normal",
"dir")""")
for k in range(100):
c.execute("""insert into nodes (
wc_id,
local_relpath,
op_depth,
repos_id,
repos_path,
parent_relpath,
presence,
kind)
values (
1,
"zig"""+str(i)+"/zag"+str(j)+"/foo"+str(k)+"""",
0,
1,
"trunk/zig"""+str(i)+"/zag"+str(j)+"/foo"+str(k)+"""",
"zig"""+str(i)+"/zag"+str(j)+"""",
"normal",
"file")""")
c.commit()
--
Philip
