0
votes
1answer
51 views
Two identical MySQL tables, one not using indexes
I have one MySQL Server (5.0.37) on a Linux Server that have many databases. Some of them (12) have each an identical table to log sensors data.
Schema of one table
CREATE TABLE `measuresHistory` (
...
4
votes
1answer
138 views
+100
MySQL Hanging Completely when `ALTER TABLE… ENABLE KEYS`
I know very little about database administration but I have to deal with some very large tables on my site.
This server has 64GB of RAM and Intel Core i7-3820 (4 x 3600 MHz). Most of everything it ...
2
votes
2answers
57 views
Are there implicit indexes in InnoDB like MyISAM?
If you have (id, a, b, c, d) table with primary key (id) and another key (a, b, c), in MyISAM that means that you also have the following implicit keys:
(a)
(a, b)
(a, b, c, id)
Is this valid for ...
4
votes
3answers
125 views
Index before or after bulk load using load infile?
I have a database with over 1B rows and two columns that are indexed (in addition to the PK).
Is it better to have the index pre-defined in the table before the load infile or better to index after ...
1
vote
1answer
103 views
Why do MySQL MyISAM table indexes go out of date?
I have few MyISAM tables, where only the auto_increment primary key is up to date with the number of columns, but not other indexes.
Any idea, why this happens?
0
votes
1answer
24 views
Which text-index I should create for xooops engine to achieve better search results?
In one of projects we use xoops engine to manage content. In mysql slow query log most of queries are following :
SELECT p.uid,f.forum_id, p.topic_id, p.poster_name, p.post_time, f.forum_name, ...
2
votes
1answer
205 views
Unique insert performance: Primary Key vs Unique Index
I have a table of unique values (domains_unique), with collumn domain varchar(255), with more than 20 mil records.
What's the fastest way to insert into the table, by keeping the domain unique ...
3
votes
3answers
549 views
InnoDB vs MyISAM with many indexes
I am not sure if there is a right or wrong answer to this question, as I suppose it severely depends on the situation, but for the sake of a mental exercise, I'll go ahead and ask it anyway:
I have a ...
3
votes
1answer
564 views
MySQL ignoring index, index cardinality is the same as number of records in the table (?!)
Everyone, I could use an extra set of eyes on an issue we've come across. Here's what we're seeing:
We're writing some code to migrate our messages to a new table called
communications. We're ...
4
votes
2answers
273 views
Less RAM than Index_length MyISAM
I'm working on a database to store "time series" data (the value of X was Y at this time). The rows themselves are very small and static in size, with the primary key consisting of two smallint ...
1
vote
2answers
264 views
All columns of table should be indexed or not mysql database?
I am having one table with 4 columns. I that one is primary key and other three columns are references to columns of other tables. I am using join of these four tables for search filter. These joins ...
3
votes
3answers
3k views
Best of MyISAM and InnoDB
Is it possible to make InnoDB to use indexes same as MyISAM instead of clustered index due to limitation of RAM while getting benefit of its concurrency performance?
