Note: The db usage in my case may not be typical.
did not work well for me:
administration tools are not user friendly
could not quite figure out how to load data from a file
Nice adminstration tools
Deployment is very simple and well explained in documentation
Speed: in my case slower than MySQL
* Preferered choice in my case
Very nice db, but deployment is rather heavy
I was considering HSQLDB as my primary choice of in memory database. After reading its history on http://en.wikipedia.org/wiki/HSQLDB :
HSQLDB is a relational database management system written in Java. It is based on Thomas Mueller's discontinued Hypersonic SQL Project.[1] He later developed H2 as a complete rewrite.
I decided to give H2 a try. Bellow is the benchmark from the H2's website, which looks quite nice. Hopefully my application will achieve similar results.
My application. I am currently running my algorithm on the top of Taste recommender engine using MySQL. A complete set of experiments for my algorithm and existing to produce results takes 3 days on a Core2 Duo machine. I need to try more than 20 different settings = 60 days. So I decided to try to speed it up. In addition I don't have permission to install db on the supercomputing cluster at my university so in memory db hopefully will solve both of my problems.
Since memory's I/O is much faster than disk I/O this should translate into significant speed up (assuming your db can fit in memory)
Could be run in embeded mode -- all you need is java and you can run it locally inside of your application (no additional sotware needs to be installed on the server etc.).
Note: I am using this setup for explorative learning algorithm; it is not a typical usage of the recommender system.
Single pass: 138 - 3,819 ms (depending on configuration)
# Create Table
CREATE TABLE taste_preferences (
user_id VARCHAR(10) NOT NULL,
item_id VARCHAR(10) NOT NULL,
preference FLOAT NOT NULL,
time_stamp VARCHAR(10),
PRIMARY KEY (user_id, item_id)
)
# Create Indexes
CREATE INDEX IDX_USER_ID ON TASTE_PREFERENCES ( USER_ID )
CREATE INDEX IDX_ITEM_ID ON TASTE_PREFERENCES ( ITEM_ID )
CREATE INDEX IDX_PREFERENCE ON TASTE_PREFERENCES ( PREFERENCE )
# Load data from file
INSERT INTO TASTE_PREFERENCES SELECT * FROM CSVREAD('/home/neil/tmp/u.txt');
see AL_CF.java for more details
Some parts of code are not well documented; the javadoc seems to be out of sync. Had to browse for this one for a while, untill found it.
// Create DB Connection
// H2
String driverName = "org.h2.Driver";
String url = "jdbc:h2:~/test";
String user = "sa";
String pwd = "";
org.h2.jdbcx.JdbcDataSource db = new org.h2.jdbcx.JdbcDataSource();
db.setUser(user);
db.setPassword(pwd);
db.setURL(url);
java.util.NoSuchElementException: Can't retrieve more due to exception: org.h2.jdbc.JdbcSQLException: The result set is not scrollable and can not be reset. You may need to use conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY). [90128-66]
Changed com.planetj.taste.impl.model.jdbc.AbstractJDBCDataModel
* NEIL -- Modified ResultSetUserIterator to fix the following Exception:
* TODO: Do it in a better way
org.h2.jdbc.JdbcSQLException: Syntax error in SQL statement INSERT INTO TASTE_PREFERENCES SET[*] USER_ID=?, ITEM_ID=?, PREFERENCE=? ON DUPLICATE KEY UPDATE PREFERENCE=? ; expected ., (, DEFAULT, VALUES, (, SELECT, FROM; SQL statement:
INSERT INTO taste_preferences SET user_id=?, item_id=?, preference=? ON DUPLICATE KEY UPDATE preference=? [42001-66]
at org.h2.message.Message.getSQLException(Message.java:89)
at org.h2.message.Message.getSQLException(Message.java:93)
at org.h2.message.Message.getSyntaxError(Message.java:103)
at org.h2.command.Parser.getSyntaxError(Parser.java:454)
at org.h2.command.Parser.parseSelectSimple(Parser.java:1445)
at org.h2.command.Parser.parseSelectSub(Parser.java:1366)
at org.h2.command.Parser.parseSelectUnion(Parser.java:1249)
at org.h2.command.Parser.parseSelect(Parser.java:1237)
at org.h2.command.Parser.parseInsert(Parser.java:826)
at org.h2.command.Parser.parsePrepared(Parser.java:343)
at org.h2.command.Parser.parse(Parser.java:265)
at org.h2.command.Parser.parse(Parser.java:241)
at org.h2.command.Parser.prepareCommand(Parser.java:209)
at org.h2.engine.Session.prepareLocal(Session.java:213)
at org.h2.engine.Session.prepareCommand(Session.java:195)
at org.h2.jdbc.JdbcConnection.prepareCommand(JdbcConnection.java:970)
at org.h2.jdbc.JdbcPreparedStatement.<init>(JdbcPreparedStatement.java:1206)
at org.h2.jdbc.JdbcConnection.prepareStatement(JdbcConnection.java:161)
at org.apache.commons.dbcp.PoolingDataSource$PoolGuardConnectionWrapper.prepareStatement(PoolingDataSource.java:302)
at com.planetj.taste.impl.model.jdbc.AbstractJDBCDataModel.setPreference(AbstractJDBCDataModel.java:420)
at com.planetj.taste.impl.recommender.AbstractRecommender.setPreference(AbstractRecommender.java:81)
at org.hrstc.taste.al.AL_CF.evaluate(AL_CF.java:243)
at org.hrstc.taste.al.AL_CF.main(AL_CF.java:80)
Solution:
INSERT INTO TASTE_PREFERENCES SET USER_ID='22', ITEM_ID='378', PREFERENCE='5.0' ON DUPLICATE KEY UPDATE PREFERENCE='5.0'
Was giving the above exception. Replaced it with:
INSERT INTO TASTE_PREFERENCES (user_id, item_id, preference) VALUES ('22', '378', '5.0') ON DUPLICATE KEY UPDATE PREFERENCE='4.0'
Then ... ON DUPLICATE KEY UPDATE PREFERENCE='4.0' part was not a standard SQL syntax (perhaps specific to MySQL).
A better way would be to use an ANSI/ISO standard command MERGE ( instead of other db specific variants ) e.g.:
MERGE INTO TASTE_PREFERENCES(user_id, item_id, preference) key(user_id,item_id) VALUES ('22', '378', '4.0')
wrote H2JDBCDataModel.java
I finaly got H2 to run (most of the changes where migrating incompatible SQL from MySQL to standard SQL)
The performance of it was rather slow:
INFO: It took ms: 2,119,766
Used memory-only mode http://www.h2database.com/html/features.html#memory_only_databases
INFO: It took ms: 140,568
Thats a 10 fold improvement
Let JVM use more memory; let db use more memory
Did not help
Installed TPTP for eclipse but does not work; could not figure out why
Using NetBeans to do profiling; is throwing some of the old error for some reason.
Fix: The problem with error was that class in jar was not correctly overwritten by NetBeans
For some reason when running from NetBeans userNeighbourhood.size = 0; but when running from command line the same files it is not
Fix: The problem with error was that class in jar was not correctly overwritten by NetBeans
Surprisingly the peformance of MySQL MyISAM and MEMORY engine are almost identical.
Performance of H2 is 10x slower than MySQL. The difference of code between two implementations is that for
H2: MERGE INTO
MySQL: INSERT ... ON DUPLICATE KEY UPDATE
INFO: It took ms: 20,574
Mar 24, 2008 11:05:09 AM org.hrstc.taste.al.AL_CF <init>
INFO: log running..
943
Mar 24, 2008 11:05:11 AM org.hrstc.taste.al.AL_CF getTestUsers
INFO: Selected userID: 421
Mar 24, 2008 11:05:11 AM org.hrstc.taste.al.AL_CF evaluate
INFO: AL Type: random
Mar 24, 2008 11:05:13 AM org.hrstc.taste.al.AL_CF evaluate
INFO: User's Stats:
[{MAE=5.0}]
Mar 24, 2008 11:05:13 AM org.hrstc.taste.al.AL_CF evaluate
INFO: It took ms: 1577
Mar 24, 2008 11:05:34 AM org.hrstc.taste.al.AL_CF evaluate
INFO: User's Stats:
[{MAE=5.0}, {MAE=0.8614681}]
Mar 24, 2008 11:05:34 AM org.hrstc.taste.al.AL_CF evaluate
INFO: It took ms: 20574
CREATE TABLE `taste`.`taste_preferences` (
`user_id` varchar(10) NOT NULL,
`item_id` varchar(10) NOT NULL,
`preference` float NOT NULL,
PRIMARY KEY (`user_id`,`item_id`),
KEY `user_id` (`user_id`),
KEY `item_id` (`item_id`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1
INFO: It took ms: 19,781
Mar 24, 2008 2:55:58 PM org.hrstc.taste.al.AL_CF <init>
INFO: log running..
943
Mar 24, 2008 2:56:00 PM org.hrstc.taste.al.AL_CF getTestUsers
INFO: Selected userID: 421
Mar 24, 2008 2:56:00 PM org.hrstc.taste.al.AL_CF evaluate
INFO: AL Type: random
Mar 24, 2008 2:56:02 PM org.hrstc.taste.al.AL_CF evaluate
INFO: User's Stats:
[{MAE=5.0}]
Mar 24, 2008 2:56:02 PM org.hrstc.taste.al.AL_CF evaluate
INFO: It took ms: 1522
Mar 24, 2008 2:56:22 PM org.hrstc.taste.al.AL_CF evaluate
INFO: User's Stats:
[{MAE=5.0}, {MAE=0.760892}]
Mar 24, 2008 2:56:22 PM org.hrstc.taste.al.AL_CF evaluate
INFO: It took ms: 19781
Mar 24, 2008 2:56:38 PM org.hrstc.taste.al.AL_CF evaluate
INFO: User's Stats:
[{MAE=5.0}, {MAE=0.760892}, {MAE=0.86437464}]
Mar 24, 2008 2:56:38 PM org.hrstc.taste.al.AL_CF evaluate
INFO: It took ms: 16243
CREATE TABLE `taste`.`taste_preferences` (
`user_id` varchar(10) NOT NULL,
`item_id` varchar(10) NOT NULL,
`preference` float NOT NULL,
PRIMARY KEY (`user_id`,`item_id`),
KEY `user_id` (`user_id`),
KEY `item_id` (`item_id`)
) ENGINE=MEMORY DEFAULT CHARSET=latin1
INFO: It took ms: 214,899
Mar 24, 2008 3:01:21 PM org.hrstc.taste.al.AL_CF <init>
INFO: loaded data
943
Mar 24, 2008 3:01:23 PM org.hrstc.taste.al.AL_CF getTestUsers
INFO: Selected userID: 421
Mar 24, 2008 3:01:23 PM org.hrstc.taste.al.AL_CF evaluate
INFO: AL Type: random
Mar 24, 2008 3:01:24 PM org.hrstc.taste.al.AL_CF evaluate
INFO: User's Stats:
[{MAE=5.0}]
Mar 24, 2008 3:01:24 PM org.hrstc.taste.al.AL_CF evaluate
INFO: It took ms: 1865
Mar 24, 2008 3:04:59 PM org.hrstc.taste.al.AL_CF evaluate
INFO: User's Stats:
[{MAE=5.0}, {MAE=0.7894972}]
Mar 24, 2008 3:04:59 PM org.hrstc.taste.al.AL_CF evaluate
INFO: It took ms: 214899
Starting DB: java -cp ./lib/hsqldb.jar org.hsqldb.Server -database.0 file:mydb -dbname.0 xdb
java -cp ./lib/hsqldb.jar org.hsqldb.util.DatabaseManager
keywords: hsqldb load data file csv
Use Text Table ; also see src/org/hsqldb/sample/load_binding_lu.sql
Error: table not found in statement [SET TABLE SOURCE] / Error Code: -22 / State: S0002
Possible Reason: Text Tables cannot be created in memory-only databases (databases that have no script file).
Tried example from src/org/hsqldb/sample/load_binding_lu.sql
CREATE TEXT TABLE binding_tmptxt (
id integer,
name varchar(12)
);
Error: Database is memory only in statement [CREATE TEXT TABLE binding_tmptxt] / Error Code: -63 / State: S1000
Solution: this statement is not allowed for in memory database; start server db instance
When trying sudo a server [org.hsqldb.util.DatabaseManager] get the following error:
java.sql.SQLException: socket creation error
Solution: none
Performance of H2 is 10x slower than MySQL. The difference of code between two implementations is that for
H2: MERGE INTO
MySQL: INSERT ... ON DUPLICATE KEY UPDATE
Changed it but did not make a difference.
Disabled/Enabled Connection pooling but did not produce significant affect either.
Since performance still is not good rewrote code for the methods that take too long; and wrote new classes optimized for my task as seen in the next blog posting ....
http://www.h2database.com/html/features.html#trace_options
TRACE_LEVEL_SYSTEM_OUT=3
Do also java code generation; this way can benchmark it against MySQL and see where the problem is.
Turn on logging finest
See performance for my AL method and optimize for it - since it is the slowest one anyway.
If performance still is not good may need to rewrite code for the methods that take too long; or write new classes optimized for my task
For example: may compute user neighborhood only for the specific items; since I need to get estimates for only a few items, etc.
HSQLDB memory mode
MySQL's MEMORY (HEAP) Storage Engine http://dev.mysql.com/doc/refman/5.0/en/memory-storage-engine.html
Comments
ultram
If you have to do it, you might as well do it right
ultram , cheap meridia , buy valium , tramadol , cheap alprazolam , cheap xanax , ambien , cheap viagra , cheap ativan , buy xanax ,
cheap viagra
Very interesting site. Hope it will always be alive!
cheap viagra , xanax , buy ativan , buy phentermine , buy cialis , cheap levitra , ultram , tramadol , ambien , valium ,
cialis
Great site. Good info
cialis , buy ativan , buy phentermine , tramadol , levitra , cheap ultram , buy ultram , alprazolam , valium , meridia ,
ativan
If you have to do it, you might as well do it right
ativan , viagra , buy levitra , buy tramadol , xanax , phentermine , buy alprazolam , cheap phentermine , cheap phentermine , xanax ,
buy viagra
If you have to do it, you might as well do it right
buy viagra , buy xanax , alprazolam , ultram , buy cialis , buy tramadol , buy meridia , ultram , buy phentermine , cheap ativan ,
buy cialis
Beautiful site!
buy cialis , buy levitra , buy valium , buy viagra , buy meridia , buy ativan , buy tramadol , ambien , cheap valium , ativan ,
levitra
It is the coolest site,keep so!
levitra , cheap ultram , cheap alprazolam , meridia , tramadol , valium , buy cialis , cheap ativan , buy viagra , ativan ,
cheap viagra
Beautiful site!
cheap viagra , buy phentermine , meridia , buy ambien , tramadol , ultram , cheap tramadol , cialis , tramadol , buy xanax ,
cheap levitra
Beautiful site!
cheap levitra , cialis , cheap phentermine , buy xanax , meridia , buy valium , valium , xanax , cheap cialis , cheap tramadol ,
levitra
I bookmarked this guestbook. Thank you for good job!
levitra , cialis , cheap meridia , ativan , cheap viagra , cheap ultram , ambien , ambien , alprazolam , cheap cialis ,
tramadol
Great site. Keep doing.
tramadol , xanax , ativan , viagra , meridia , buy ativan , levitra , cheap alprazolam , ultram , xanax ,
cheap xanax
If you have to do it, you might as well do it right
cheap xanax , cialis , buy levitra , meridia , ambien , cheap ambien , cheap viagra , ambien , ultram , phentermine ,
buy tramadol
If you have to do it, you might as well do it right
buy tramadol , meridia , cheap phentermine , xanax , alprazolam , cheap levitra , ambien , cheap ambien , phentermine , buy meridia ,
alprazolam
If you have to do it, you might as well do it right
alprazolam , buy valium , cheap meridia , ultram , buy viagra , buy xanax , cheap ativan , cheap levitra , ultram , cheap viagra ,
phentermine
Great site. Good info
phentermine , cheap ultram , cheap meridia , ativan , buy valium , ambien , valium , buy ativan , cialis , levitra ,
viagra
I bookmarked this guestbook. Thank you for good job!
viagra , valium , cheap levitra , cheap ambien , alprazolam , buy ultram , ultram , cheap meridia , cheap phentermine , cheap meridia ,
meridia
Great work,webmaster,nice design!
meridia , levitra , buy ultram , ativan , cheap alprazolam , buy phentermine , meridia , cialis , cheap ambien , alprazolam ,
buy viagra
Great work,webmaster,nice design!
buy viagra , cialis , ambien , cheap ativan , cheap xanax , meridia , ambien , tramadol , cheap cialis , buy viagra ,
buy cialis
It is the coolest site,keep so!
buy cialis , buy ativan , cheap xanax , cheap tramadol , ambien , tramadol , buy ambien , meridia , ambien , buy phentermine ,
cheap levitra
It is the coolest site,keep so!
cheap levitra , cialis , alprazolam , meridia , cheap valium , cialis , ambien , cheap ativan , buy cialis , ambien ,
levitra
Perfect site, i like it!
levitra , xanax , tramadol , ativan , buy valium , meridia , phentermine , ultram , phentermine , cheap ativan ,
ativan
Incredible site!
ativan , buy viagra , viagra , valium , buy ambien , buy levitra , buy phentermine , cheap xanax , ultram , cialis ,
cheap ambien
It is the coolest site,keep so!
cheap ambien , cialis , alprazolam , cheap valium , cheap ativan , buy meridia , cheap ultram , levitra , levitra , buy viagra ,
meridia
Very interesting site. Hope it will always be alive!
meridia , xanax , ativan , ultram , ultram , buy valium , buy phentermine , levitra , ambien , tramadol ,
xanax
Incredible site!
xanax , viagra , meridia , ativan , cheap cialis , levitra , ultram , cheap ambien , cheap ativan , buy xanax ,
viagra
Perfect site, i like it!
viagra , levitra , phentermine , cialis , ambien , valium , ultram , xanax , cheap ativan , cheap tramadol ,
cheap valium
It is the coolest site,keep so!
cheap valium , cheap levitra , cheap meridia , buy ambien , buy cialis , alprazolam , cheap ultram , alprazolam , buy tramadol , buy phentermine ,
cheap alprazolam
Perfect work!
cheap alprazolam , buy ambien , valium , phentermine , viagra , viagra , cialis , cheap ambien , meridia , levitra ,
buy viagra
Nice site! Thank you!
buy viagra , buy ultram , cheap meridia , buy xanax , viagra , cialis , cheap valium , buy ambien , phentermine , cheap phentermine ,
cheap alprazolam
Very interesting site. Hope it will always be alive!
cheap alprazolam , cheap ultram , buy ambien , meridia , buy alprazolam , cheap xanax , cialis , ativan , cheap xanax , buy viagra ,
levitra
Incredible site!
levitra , cialis , buy valium , buy ambien , meridia , buy viagra , levitra , cheap alprazolam , cheap ativan , ativan ,
tramadol
Great site. Good info
tramadol , levitra , cheap viagra , ambien , cheap tramadol , valium , buy meridia , cialis , cheap meridia , alprazolam ,
cheap phentermine
Great .Now i can say thank you!
cheap phentermine , ativan , ultram , tramadol , cialis , buy viagra , viagra , valium , buy alprazolam , buy ambien ,
buy viagra
Great work,webmaster,nice design!
buy viagra , buy levitra , cheap meridia , buy ambien , valium , buy alprazolam , cialis , phentermine , ativan , levitra ,
cheap ultram
If you have to do it, you might as well do it right
cheap ultram , buy ativan , buy levitra , phentermine , xanax , cheap phentermine , buy alprazolam , meridia , valium , cheap viagra ,
buy cialis
Nice site! Thank you!
buy cialis , levitra , ativan , buy alprazolam , phentermine , cheap xanax , tramadol , cheap meridia , alprazolam , buy ativan ,
cheap cialis
Excellent site. It was pleasant to me.
cheap cialis , cheap ativan , alprazolam , buy ultram , cheap viagra , ativan , buy cialis , ambien , valium , phentermine ,
buy cialis
Perfect site, i like it!
buy cialis , xanax , alprazolam , ultram , levitra , buy levitra , viagra , buy ultram , buy ativan , cheap meridia ,
cheap ambien
Perfect work!
cheap ambien , buy phentermine , cheap valium , levitra , cialis , ultram , buy ultram , cheap meridia , cheap alprazolam , viagra ,
buy levitra
It is the coolest site,keep so!
buy levitra , valium , buy alprazolam , xanax , viagra , buy ultram , cheap ativan , tramadol , cheap ambien , cheap cialis ,
alprazolam
I bookmarked this guestbook. Thank you for good job!
alprazolam , tramadol , cheap xanax , ultram , cheap tramadol , cheap phentermine , cheap ativan , tramadol , valium , buy alprazolam ,
phentermine
Incredible site!
phentermine , meridia , valium , buy xanax , ultram , ultram , cheap cialis , cheap alprazolam , buy levitra , cheap meridia ,
cheap ambien
Incredible site!
cheap ambien , cheap levitra , ultram , cheap alprazolam , cheap phentermine , tramadol , buy levitra , cheap ativan , cheap viagra , valium ,
cheap xanax
It is the coolest site,keep so!
cheap xanax , cheap levitra , phentermine , cheap alprazolam , viagra , buy tramadol , phentermine , valium , ambien , buy xanax ,
ativan
I want to say - thank you for this!
ativan , phentermine , cheap alprazolam , cheap meridia , cheap xanax , cheap tramadol , buy ativan , ultram , cheap alprazolam , meridia ,
tramadol
Great site. Good info
tramadol , viagra , ativan , viagra , alprazolam , cheap ultram , buy valium , viagra , buy cialis , levitra ,
meridia
Great site. Keep doing.
meridia , cheap valium , phentermine , buy tramadol , cialis , meridia , alprazolam , ativan , meridia , cheap viagra ,
ambien
Incredible site!
ambien , buy xanax , buy ativan , cheap ativan , buy cialis , xanax , viagra , meridia , cheap valium , levitra ,
cheap levitra
It is the coolest site,keep so!
cheap levitra , buy xanax , buy ambien , tramadol , cheap alprazolam , cheap viagra , ativan , meridia , ambien , phentermine ,
buy meridia
Great .Now i can say thank you!
buy meridia , cheap ambien , valium , buy xanax , ativan , cheap phentermine , cheap cialis , buy ambien , buy viagra , phentermine ,