68,928 reputation
1070160
bio website
location Jersey City, NJ (USA)
age 49
visits member for 3 years, 9 months
seen 9 mins ago

One of JEHOVAH's Witnesses (TV)

Seasoned MySQL DBA (SCMDBA) since 2007-08-11

Profile for RolandoMySQLDBA on Stack Exchange, a network of free, community-driven Q&A sites


2m
comment Strange MySQL replication error 1146 (Table doesn't exist)
I have four(4) questions : Q1) Do you only run backups on Slave B ? Q2) What is the storage engine of the table course_location_tracks ? Q3) Did you create that table with CREATE TABLE course_location_tracks or CREATE TEMPORARY TABLE course_location_tracks ? Q4) Did you stop replication with STOP SLAVE; or STOP SLAVE IO_THREAD; ?
1h
comment Implement a Parent-Level Count in Binary Search Tree
I have a question on the how you want GetFamilyTree(id,3) to behave. Do you want GetFamilyTree(id,3) to bring back a tree whose height is 3 or do you want the return list liimited by the first three ids in the output ?
1h
comment high mysql sent traffic
Next questions: Is DB Server being accessed by remote connections from other servers Apache/PHP ? Could those DB Connections be presented as localhost via some bind address scheme ?
1h
comment high mysql sent traffic
Is your host provider doing any monitoring ? Does your host provider have any mysql user accounts you do not know about ?
2h
comment high mysql sent traffic
Your global status is showing your all traffic for the mysqld process. The session is just you. Look for all DB Connections whose processes do not originate with your application.
3h
comment Find highest level of a hierarchical field: with vs without CTEs
@MarceloAymone Exactly. I never use as A. Other dialects of SQL may require as A.
3h
comment Find highest level of a hierarchical field: with vs without CTEs
@MarceloAymone The A is just an alias for the subquery
1d
comment MySQL Multi Count
Go to my answer and look at the upper left hand corner. You will see a check mark. If you click the check mark, it will turn green. That's when it is marked accepted.
1d
comment Is it ok to have 40+ columns in a table
Here is a 3-year-old post about this : dba.stackexchange.com/questions/3972/too-many-columns-in-mysql/…
1d
comment MySQL Multi Count
I updated my answer
2d
comment optimize my query mysql
You should change the storage engine back to InnoDB. Then, upgrade to MySQL 5.6.21.
2d
comment optimize my query mysql
Based on that error message, you are not using MySQL 5.6 because FULLTEXT indexes are supported in InnoDB now (dev.mysql.com/doc/refman/5.6/en/innodb-fulltext-index.html). If you upgrade to MySQL 5.6, you can make FULLTEXT indexes in InnoDB.
2d
comment Duplicate values
Please mark it accepted by clicking on the check mark
Nov
25
comment Increase performance WITHOUT adding indexes
@BillKarwin you are right. It's just really band-aid to get around not rewriting queries and creating supporting indexes for them. I have had past clients that wanted this and were satisfied with some performance improvements. Of course, those clients had like 192GB RAM and more. RAM disks are not really for small to midsize DB Servers.
Nov
25
comment Problems with migration from Amazon RDS MySQL to MariaDB
Your question is unclear. Is MariaDB in a bare metal server, EC2, or another VM environment ? Did you tune my.cnf in the new server to match the settings you had in MySQL RDS ?
Nov
25
comment Duplicate values
DBA SE Community : Please don't close this. I have the answer (dba.stackexchange.com/a/83589/877)
Nov
25
comment Is this update, select combination query thread safe?
At first, I was thinking that the first SELECT triggers the lock and the second SELECT does the actual retrieval. Now that I think about it, the SELECT id INTO @available_id from seats WHERE taken is null limit 1 FOR UPDATE; is most likely sufficient.
Nov
23
comment How much space is needed to reclaim space from a table in INNODB
My answer gives you an idea how big a table will be during and after OPTIMIZE TABLE. Just try the queries on a couple of midsize tables that need shrinking. If the temp tables have a good size, then my queries will accurate predict how much space you will need.
Nov
21
comment How to get the SUM between dates in a WHERE clause?
I added ORDER BY BB.date DESC ,AA.id to make dates go backwards and make id go forwards within dates.
Nov
21
comment WordPress MySQL writes during “Flush Tables With Read Lock” are rejected instead of being queued
Please look back at my answer. I didn't say FLUSH TABLES LOCK;. I said FLUSH TABLES WITH READ LOCK;.