Re: AWS forcing PG upgrade from v9.6 a disaster

2021-06-06 Thread Dean Gibson (DB Administrator)

On 2021-05-29 13:35, Andrew Dunstan wrote:

On 5/29/21 3:59 PM, Dean Gibson (DB Administrator) wrote:

Meanwhile, I've been doing some checking.  If I remove "CAST(
license_status AS CHAR ) = 'A'", the problem disappears.  Changing the
JOIN to a RIGHT JOIN, & replacing WHERE with ON, also "solves" the
problem, but there is an extra row where license_status is NULL, due
to the RIGHT JOIN.  Currently trying to figure that out (why did the
CAST ... match 'A', if it is null?)...

Why are you using this expression? It's something you almost never want
to do in my experience. Why not use the substr() function to get the
first character?

cheers

andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com


Although it doesn't matter in this case, I do it because in general, it 
changes the type of the value from CHAR to bptext or whatever it is, & 
that has causes comparison issues in the past.  It's just a matter of 
habit for me when working with CHAR() types.


But this case, where it doesn't matter, I'd use LEFT().


dexter on AWS RDS auto tune queries

2021-06-06 Thread Ayub Khan
Other than Dexter, Is there an auto tune or query performance indicator for
postgres ?
Also which are the most commonly used monitoring (slow query, cpu, index
creation for missing indexs ) tools being used for postgres ?

--Ayub


Re: dexter on AWS RDS auto tune queries

2021-06-06 Thread Julien Rouhaud
Hi,

On Mon, Jun 7, 2021 at 12:52 PM Ayub Khan  wrote:
>
> Other than Dexter, Is there an auto tune or query performance indicator for 
> postgres ?

It depends.  If you're on AWS or any other cloud, probably nothing
apart from tools based on logs or standard SQL execution (so nothing
based on third party extension).

> Also which are the most commonly used monitoring (slow query, cpu, index 
> creation for missing indexs ) tools being used for postgres ?

There are a lot of projects documented at
https://wiki.postgresql.org/wiki/Monitoring




Re: dexter on AWS RDS auto tune queries

2021-06-06 Thread Christophe Pettus



> On Jun 6, 2021, at 21:51, Ayub Khan  wrote:
> Other than Dexter, Is there an auto tune or query performance indicator for 
> postgres ?

Generally, auto-creating indexes isn't a great idea.  I respect the work that 
went into Dexter, but it's much better to find the queries and study them, then 
decide if index creation is the right thing.

RDS has Performance Insights, which is a very useful tool for finding where the 
load on your server is actually coming from.