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Testing InnoDB “Barracuda” format with compression

 | April 23, 2008 |  Posted In: Insight for DBAs


New features of InnoDB – compression format and fast index creation sound so promising so I spent some time to research time and sizes on data we have on our production. The schema of one of shards is

in fact this is not exact schema – difference is we are using DEFAULT CHARSET=utf8, which seems not working with fast index creation (bug 33650) , so I use latin1 for tests. Also we actually store ‘bodyuc’ as compressed field, doing compress()/uncompress() to store/restore. To test InnoDB compression I use only uncompressed text, though I tested compression on compress()-ed data just to see if there is any benefit from index compression.

For test I use dump created with mysqldump, final size 30286M.
To create InnoDB compression table I use ENGINE=InnoDB KEY_BLOCK_SIZE=8 and to test fast index creation I create table only with primary key, without additional indexes.

Numbers I got:

load dump into table with default format and all indexes (case 1) – 152m34.792s
size of final .ibd file for (case 1) – 43032M

What if load data and indexes separately:

load dump into table with default format and without indexes (case 2a) – 59m12.575s
size of .ibd after (case 2a) – 36968M
create all indexes (case 2b) – 18min46.05s
size of .ibd after (case 2b) – 40400M

So as you see time to load (case 2) (with fast create index way) is faster almost two times and space decreased by 6%.

Now with compressed table:

load dump into table with default format and all indexes (case 3) – 228m55.251s (time took 1.5 times longer than (case 1) )
size of final .ibd file for (case 3) – 16284M (space ratio is 0.37 compare to (case 1) )

What if load data and indexes separately:

load dump into table with default format and without indexes (case 4a) – 71m10.760s (longer 1.2 times than (case 2a))
size of .ibd after (case 4a) – 13208M (smaller 0.35 times)
create all indexes (case 4b) – 42m54.63sec (longer 2.28 times)
size of .ibd after (case 4b) – 14968M (smaller 0.37 times)

Total time for (case 4) , 6844 sec, took 1.46 times longer than (case 2) , 4678 sec, but space decreased by even more ( 0.37 from original)

Also interesting to note that fast index creation allows to load time two time faster than usual load.

Ok, There are a lot of numbers, let me summarize it:

Test Load time, sec Size, MB
Baseline (1), default format, usual load 9154 43032
default format, fast index creation 4678 (0.51)* 40400 (0.93)
compress format, default load 13735 (1.50) 16284 (0.38)
compress format, fast index creation 6844 (0.74) 14968 (0.35)

* – ratio to baseline

So in conclusion
– Fast Index creation allows to speedup load 2 times (even indexes fit into memory)
– Load in compress format slower by 30-50%
– Table in compress format takes only 1/3 of original table

Of course we also expect significant performance gain for I/O bound queries in case of compression tables, this is topic for different research.

Vadim Tkachenko

Vadim Tkachenko co-founded Percona in 2006 and serves as its Chief Technology Officer. Vadim leads Percona Labs, which focuses on technology research and performance evaluations of Percona’s and third-party products. Percona Labs designs no-gimmick tests of hardware, filesystems, storage engines, and databases that surpass the standard performance and functionality scenario benchmarks. Vadim’s expertise in LAMP performance and multi-threaded programming help optimize MySQL and InnoDB internals to take full advantage of modern hardware. Oracle Corporation and its predecessors have incorporated Vadim’s source code patches into the mainstream MySQL and InnoDB products. He also co-authored the book High Performance MySQL: Optimization, Backups, and Replication 3rd Edition.


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