Comments for code.openark.org

Comment on MySQL joins: ON vs. USING vs. Theta-style by shlomi

shlomi — Thu, 23 May 2013 04:17:20 +0000

What's query number two?

Comment on MySQL joins: ON vs. USING vs. Theta-style by Jayesh

Jayesh — Wed, 22 May 2013 20:46:30 +0000

My apologies. I might have posted incomplete question.

query 1:

table_1 join table_2 using(col 1) where table_1.date_1 >= table_2.date_2 and table_1.date_1 >= table_2.date_3 and table_1.date_1 = table_2.date_2 and table_1.date_1 >= table_2.date_3 and table_1.date_1 < table_2.date_4);

What is the difference between the execution and expected results from the 2 queries?

Query 1 returned on 10% of records from query_1 while query 2 returned the desired result.

Comment on MySQL joins: ON vs. USING vs. Theta-style by Jayesh

Jayesh — Wed, 22 May 2013 20:41:20 +0000

Hi,

I had a doubt with respect to the ANSI syntax for join. How would the execution of the query change if i use the two queries given below -

query 1:
table_1 join table_2 using(col 1) where table_1.date_1 >= table_2.date_2 and table_1.date_1 >= table_2.date_3 and table_1.date_1 = table_2.date_2 and table_1.date_1 >= table_2.date_3 and table_1.date_1 < table_2.date_4);

When i used query 1, my total records were reduced from 3 million to 600k. But it was not the case when i used the query 2.

I am unable to understand what went wrong in query 1.

Comment on Reasons to use innodb_file_per_table by innodb_file_per_table for existing MySQL database | Olof Larsson

innodb_file_per_table for existing MySQL database | Olof Larsson — Wed, 22 May 2013 13:37:41 +0000

[...] http://code.openark.org/blog/mysql/reasons-to-use-innodb_file_per_table [...]

Comment on On compiling TokuDB from source by Alexei

Alexei — Mon, 20 May 2013 12:51:24 +0000

@shlomi I have read article "Benchmarking Percona Server TokuDB vs InnoDB" on Mysqlperformanceblog and decided not to waste my time playing with TokuDB installation and decided to remain on PerconaDB

Comment on On compiling TokuDB from source by shlomi

shlomi — Mon, 20 May 2013 11:44:59 +0000

@Alexei,
Now trying this for myself, I get same error as yours -- did you solve this?

Comment on SQL: selecting top N records per group by shlomi

shlomi — Thu, 16 May 2013 05:14:38 +0000

@Erich,

Yes, the use of commas assume no commas in values; I also sometimes use char(0) or char(9) which nobody uses within texts

Comment on SQL: selecting top N records per group by Erich

Erich — Tue, 14 May 2013 09:19:07 +0000

this is just what i needed - i suggest using char(1) rather the ',' tho

Comment on On compiling TokuDB from source by shlomi

shlomi — Tue, 07 May 2013 05:45:24 +0000

Hrm... So my comment on mysqlperformanceblog related to myself trying to do the normal "./configure && make" from the Percona build tarball. I haven't tackled the error you're describing with the bash script. However, I see you are using the "new method" of building the source, whereas I was using the "old method"; haven't tried the new one as yet.

Comment on On compiling TokuDB from source by Alexei

Alexei — Mon, 06 May 2013 18:17:14 +0000

I did not compiled by myself, just executed script:

scripts/make.mysql.bash --git_tag=tokudb-7.0.1 --mysql=mariadb-5.5.30 --cc=gcc --cxx=g++

I saw your comment with the same error on mysqlperformanceblog. Thanks anywasy for your answer!