Hi Team! Any idea whats causing this runtime error...

# apollo-kotlin

[Ife]

Hi Team!
Any idea whats causing this runtime error:

I'm using com.apollographql.apollo:apollo-normalized-cache-sqlite v4.0.0 which matches apollo version

Apollo: unhandled exception
java.lang.Exception: Unable to read a record from the database
at com.apollographql.apollo.cache.normalized.sql.SqlNormalizedCache.loadRecord(SqlNormalizedCache.kt:25)
Caused by: android.database.sqlite.SQLiteException: Can't downgrade database from version 3 to 1

[bod]

I think from previous conversations that you were trying the new cache. Which upgraded the database to the new format. Now the previous version is unable to read it anymore.

[bod]

Deleting the database file should do it.

[Ife]

yep! that did fixed it!
cheers man!

[Ife]

Another qq mate (dont recall if you already answer in our last convo)

can you write into paginated cache like so via the apolloStore.writeOperation?
Actually, was able to write, but the

messages({"after":"","first":20,"receiver_id":12,"sender_id":25})

I attempted it but couldnt find the data once written It still maintained the old data

[bod]

Hmm yes when you do this, it should replace the current list with the one you pass.

[Ife]

right
i know the edges is being updated correctly. my guess however is that the first argument in the paginated when querying is not dynamic, it'll always look for first:20 for example and there's nothing of such in the cache db when i used the intelliJ viewer.

[Ife]

I wonder if there's anyway around this..

[bod]

What's supposed to happen is that you should see a messages({"receiver_id":12,"sender_id":25}) field in the cache. I.e. after and first should be omitted.

[Ife]

awesome!
just removed the first:20 arg from the actual query that way it returned the updated data each time.

[Ife]

appreciate it!

[Ife]

of course that will impact perf depending on messages count when first is removed 😀

[Ife]

@bod how do we force *.wal file to be immediately sync'd with the actual db on ios?

As you prob know, writes on iOS goes into *.wal` file whilst preserving the actual db for reads . This doesnt immediatly sync up which leads to two sets of data. At runtime, the wal file is not available for reads, causing app to fetch from network.

[Ife]

How can we ensure immediate writes are made available to actual db so it can be part of the data when querying?

Looked at the apolloStore api, cant see anything explicitly enforcing this

[Ife]

Screenshot 2025-06-07 at 22.07.47.png

[bod]

as far as I know this should just work, without a need to do anything explicit