469,945 Members | 2,262 Online
Bytes | Developer Community
New Post

Home Posts Topics Members FAQ

Post your question to a community of 469,945 developers. It's quick & easy.

sqlite3 import performance

hi folks --

a quick python and sqlite3 performance question. i find that
inserting a million rows of in-memory data into an in-memory database
via a single executemany() is about 30% slower than using the sqlite3
CLI and the .import command (reading the same data from a disk file,
even.) i find this surprising, executemany() i assume is using a
prepared statement and this is exactly what the .import command does
(based on my quick perusal of the source.)

is this discrepancy to be expected? where is the overhead coming

for full disclosure: the python code is at the end; run it first to
generate the data file. to test the CLI, i couldn't find a better way
than to create an init file "sqlcmds" containing

create table test (k int primary key, v int not null);
..import data test

and then run

time sqlite3 -init sqlcmds ':memory:' '.quit'

the python code is

#!/usr/bin/env python

import sqlite3, random, timeit

con = None
def prepare():
global con, cur


def ins():
global con, data, cur

cur.execute('drop table test')
cur.execute('create table test (key int primary key, val int not

cur.executemany("INSERT into test (key, val) values (?, 10)",data)

hs = {}

print 'generating data...'
size = 1000000
data = [[a] for a in random.sample(xrange(10000000), size)]
print 'done!'

# save the data for the sqlite3 CLI
f = file('data', 'w')
f.writelines([str(a[0])+"|10\n" for a in data])

print 'testing ' + str(size) + ' inserts...'
# test 100K inserts
t = timeit.Timer(stmt='ins()',
setup="import sqlite3\nfrom __main__ import prepare, ins
print t.repeat(3,1)

thanks, ben
Sep 5 '08 #1
0 1555

This discussion thread is closed

Replies have been disabled for this discussion.

Similar topics

2 posts views Thread by Harold Shore | last post: by
2 posts views Thread by John Machin | last post: by
66 posts views Thread by mensanator | last post: by
reply views Thread by jim-on-linux | last post: by
4 posts views Thread by Simon | last post: by
13 posts views Thread by mark carter | last post: by
33 posts views Thread by Stef Mientki | last post: by
3 posts views Thread by milan_sanremo | last post: by
By using this site, you agree to our Privacy Policy and Terms of Use.