How to check rows for continuity? - sql

Question

I have an operation that if it fails - it retries 5 times and then gives up. Resulting in following log table:
LogId OpId Message
1 4 Retry 1...Failed
2 4 Retry 2...Failed
3 4 Retry 3...Failed
4 4 Retry 4...Failed
5 4 Retry 5...Failed
6 4 Max Retries exceeded - giving up
Sometimes, it will succeed after retry, which means that I'll never see the Max Retries exceeded - giving up entry within that OpId.
And that I what I am trying to identify. Operations that were forced to go into retries (e.g there is a Retry X... entry), but there isn't a Max Retries exceeded - giving up entry because the retry succeeded at some point.
I tried using Window functions, and I think that might the way to go but I am not sure how to actually identify what I want.
P.S. Added auto-incrementing field per #GMB

Answer 1

For this dataset, you might be able to just use aggregation:
select opId
from mytable
group by opId
having
max(case when message like 'Retry%' then 1 end) = 1
and max(case when message = 'Max Retries exceeded - giving up' then 1 end) is null
This gives you the list of opId for which at least one message starts with 'Retry' and that have no message equal to 'Max Retries exceeded - giving up'.

Answer 2

Anything that goes into retries will have a "Retry 1...Failed" entry, so (assuming opid is different for each set) a self join would probably work.
SELECT opId
, CASE WHEN tGU.opId IS NULL THEN 'Eventually Succeeded' ELSE 'Gave Up' END AS final
FROM theTable AS t1
LEFT JOIN theTable AS tGU
ON t1.opId = tGU.opId
AND tGU.Message = "Max Retries exceeded - giving up"
WHERE t1.Message = "Retry 1...Failed"
If you just want ops that eventually succeeded, you can omit the CASE WHEN stuff (I really just meant it as an example), and just and AND tGU.opId IS NULL to the WHERE clause.
However, and I don't think there is really a way around this, ops currently retrying will be considered "eventually successful". (Due to the nature of the data, you cannot really know "eventually succeeded"; only "didn't or hasn't yet given up".)
Also, perhaps it is a wording thing, but what if "Retry 1" succeeds? (Or does "Retry 1...Failed" really intend to mean something like "Attempt 1 failed, retrying"?)

Answer 3

https://dbfiddle.uk/?rdbms=sqlserver_2019&fiddle=307881806d4da72e5f37c080e419e00b
Given a table that looks something like
CREATE TABLE dbo.so_60047052(OpId int, Message varchar(50));
insert into dbo.so_60047052
SELECT *
FROM
(
VALUES
(4,'Retry 1...Failed')
, (4,'Retry 2...Failed')
, (4,'Retry 3...Failed')
, (4,'Retry 4...Failed')
, (4,'Retry 5...Failed')
, (4,'Max Retries exceeded - giving up')
-- Some failure but not all
, (5,'Retry 1...Failed')
, (6,'Retry 1...Failed')
, (6,'Retry 2...Failed')
, (8,'Retry 1...Failed')
, (8,'Retry 2...Failed')
, (8,'Retry 3...Failed')
, (8,'Retry 4...Failed')
)D(OpId, Message);
You can attack it a few different ways
-- Show me anything that got into a terminal status
SELECT
D.OpId
, D.Message
FROm
dbo.so_60047052 AS D
WHERE
D.Message = 'Max Retries exceeded - giving up';
-- Show me the "last" failing message where it didn't hit max retries
-- Last is in quotes as it's only last because the text sorts that way
SELECT
D.OpId
, D.Message
FROM
dbo.so_60047052 AS D
WHERE
NOT EXISTS
(
SELECT *
FROM dbo.so_60047052 AS DI
WHERE DI.Message = 'Max Retries exceeded - giving up'
AND DI.OpId = D.OpId
)
AND D.Message =
(
SELECT MAX(DI.Message)
FROM dbo.so_60047052 AS DI
WHERE
DI.OpId = D.OpId
);
If you have a table that records all the OpId, beyond the ones that have trouble, you can then build out a set that "had no issues", "had transient issues", "failed" based on