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Comment by Slawomir on Splitting large database into smaller ones

Thank you. Do you agree that it's not possible to have one common namespace (database) hosting all the stored procedures, then be able to invoke it as shared.sp_get_info() in the context of another...

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Comment by Slawomir on Splitting large database into smaller ones

We think so; we insert millions of rows a day and concurrency is insane. Scaling up (larger instances) will eventually hit a hard limit. We are in the same boat as these guys were back in 2012:...

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Comment by Slawomir on Managing 100s of similar databases

More info added based on your feedback. THANKS!

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Comment by Slawomir on Managing 100s of similar databases

The reason isn't just "good" - I could fight that one - it's mandated by the regulations.

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Comment by Slawomir on Point in time recovery with mariabackup

right, that was my understanding too reading the docs and it's quite inconvenient... yet another tool (mysqlbinlog) thrown into the mix and the opportunity for an error

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Comment by Slawomir on Minimizing MySQL downtime during OS update?

In #4, when the FLUSH... command finishes we'd issue the CHANGE MASTER TO...

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Comment by Slawomir on Under load, the following job-queue design does not...

Jobs take sub-second to execute. There is an alarm whenever/if jobs were to take more than 3 std dev. The alarm works. There is about 50 jobs per second. The job_queue table has 4 columns,...

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Comment by Slawomir on Under load, the following job-queue design does not...

Jobs may fail for various reasons, hence the status column. Queuing is a safety measure to ensure that if there is a backend processing problem, the queue will grow but the backend will have time to...

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Comment by Slawomir on Under load, the following job-queue design does not...

I have rewrote my code to not rely on row_count(), just always select whatever UPDATE changed and deal with the results in the client. All previous problems got resolved.

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Comment by Slawomir on Which FLUSH command before taking EBS volume snapshot?

It's too slow and too heavy on local resources (CPU, disk) compared to a volume snapshot. I recommend this article as it's universally applicable: engineering.shopify.com/blogs/engineering/…

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guideline for calling optimize table after alter table?

Should I be calling 'optimize table' when changing datatypes of columns, adding indexes or dropping indexes, assuming a table with millions of rows, heavily used, both for reading and writing...

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Mirror data on local SSD storage to conserve EBS I/O?

I have an AWS instance with local (ephemeral) SSD storage backed by a permanent EBS storage. Is it possible to configure the local storage to act as a mirror/cache for row data in MySQL? I do not wish...

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Trying to fit indexes in memory: partitioning vs compression or neither?

I have a "transaction" table that grows at about 150k rows-per-day rate. 97% of user aggregate queries refer to the last 3 months of data and must run very efficiently. Trimming older transaction data...

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PROCEDURE ANALYSE suggests to turn timestamp into CHAR(19)

Using Procedure Analyse() under MySQL 5.6.30 on a table with about 4 million rows makes the following recommendations:change timestamp to char(19)tinyint to ENUM (I noticed it's overzealous with ENUMS...

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Efficiency of foreign keys

If I have a table A which has a composite (two column) foreign key on another table B, should I:a) create a two-column key in B to match the foreign key in A?b) or, MySQL automatically creates the...

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Possible to have a statement in stored procedure outside of current transaction?

During a series of statements in my stored procedure I wish to log an entry by inserting a record. That record needs to survive even if the overall SP ends up rolling back.Is this possible?

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preferred order of columns in the key

If I have a table like so:table T ( account_id bigint, event_date datetime ... );and later make queries like so:select ...from Twhere account_id = 'ABC' and event_date >= '2016-01-01'Does the order...

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MySQL overhead of calling a Stored Procedure

Within Java, we access MySQL (v5.5.40) via JDBC -- a prepare statement, setting parameters then calling the stored procedure. It appears that every execute() has the overhead of 4 meta-calls (per MySQL...

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Acceptable deadlock rate and how to diagnose them

Our system is doing about 50 inserts per second. During ~2 hour period we are seeing up to 3 of "Deadlock found when trying to get lock; try restarting transaction" conditions. Yes, the client restarts...

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Simple conditional update causing a deadlock hints at MySQL bug

I have a very simple "inventory management" update that under load causes InnoDB to deadlock and rollback one of the threads. There doesn't appear to be any ordering issue here, so I'm at a loss how to...

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