Automatically delete documents using filters

[Olimpia_Andreea_Brendea]

Hi,
I have to automatically delete/expire documents based on two conditions:
-they have field1= “A”
-they have the date_field_b greater that 6 months with respect to current date

I found out TTL Partial Index documentation but I have some issues to implement this.
Can anyone help me?

[steevej (Steeve Juneau)]

We might be able to help you if share exactly what you tried and more details about

@Olimpia_Andreea_Brendea

some issues to implement this.

Sample documents are always useful too.

[Olimpia_Andreea_Brendea]

@steevej

able to help you if share exactly what you tried and more details about

I’ve got some documents structured as follows:
id: A1234
publishDate: 2023-12-21T17:00:50.348+00:00
flag : Done

I would like to automatically delete all documents where flag=Done and publishDate=publishDate+6months.
I found out some documentation on TTL Index, but I do not know where to start

[steevej (Steeve Juneau)]

Something along the lines:

db.eventlog.createIndex(
  { "timestamp": 1 },
  { partialFilterExpression: { "sensor": { $eq: "40.761873, -73.984287" } } },
  { expireAfterSeconds: 3600 } )

which is an example given at

TTL Indexes — MongoDB Manual

The partialFilterExpression

{ flag : 'Done' }

should work.

You would need to replace 3600 to what ever value correspond to 6 months, which could be tricky because not every months have the same number of seconds.

[Olimpia_Andreea_Brendea]

I’ve tried and it gave me an error: “MongoServerError: Invalid field specified for createIndexes command: commitQuorum”. I’ve got MongoDB version 1.39 : does it not support the ttl partial index?

[steevej (Steeve Juneau)]

@Olimpia_Andreea_Brendea

MongoDB version 1.39

How did you get the version? I do not know the version history of TTL index, but you might not be able to implement your use-case directly. But before jumping to conclusion, please share the exact command that you tried.

The following worked for me.

c.createIndex(
    { publishDate : 1 } ,
    { partialFilterExpression : { flag : "done"} ,
      expireAfterSeconds : 36000 }
)

It looks like the syntax from the example I got from the link I provided is wrong. What I understand is that both options partialFilterExpression and expireAfterSeconds have to be inside the same parameter object.

[steevej (Steeve Juneau)]

Dear @Olimpia_Andreea_Brendea, I spent some of my free time to work on your issue, I would appreciate a followup and perhaps closure by marking one of my post as the solution.

Ad Thanks Vance