#Sqlite transaction log full

If the two tie, we take the cell with the greater value. When merging cells, we take the cell with the highest logical clock. Each cell contains a logical clock that is incremented on mutation of that cell.

This allows us to find all cells that were create/updated after a given db_version. Regarding decision (5), each cell that is written also has the db_version recorded along side it.

#Sqlite transaction log full

If we kept full fidelity history of what things looked like at every transaction, high frequency updates would present a problem. Will not overload the network with sync events.Will not increase the number of entries in crsql_changes.Will not increase the size of the databases.Given we only store current state, it does not matter if someone updates some set of rows thousands of times a second. To see how we'll better support transactional guarantees in the future, see How CR-SQLite Transactions Work Tomorrow UpsideĪside from minimal storage footprint, the other big advantage of the current approach is in dealing with high frequency writes. Asking for help, clarification, or responding to other answers. So while you can commit atomic transactions locally, when syncing a transaction might be split up across two db_versions unless you've written a custom networking layer. Thanks for contributing an answer to Stack Overflow Please be sure to answer the question.Provide details and share your research But avoid. Wait for cr-sqlite to include a full fidelity transaction log for these use cases.Like 3 but split into chunks on transaction boundaries. In your network layer, keep a log of changeset batches to sync.In your network layer, sync all changes from N to current db_version in a single transaction.In your network layer, sync after every commit.Handle it in your application by understanding this limitation.What this means is that when asking for all changes with a given db_version, you will be missing any values for that transaction that were overwritten by a later transaction. Given this, later transactions can overwrite values from earlier transactions. The exception comes from the fact that cr-sqlite only stores the latest state (decision 4). When asking crsql_changes for all changes with a given db_version you will get all updates committed in that transaction with one exception. Syncing TransactionsĮvery commit to the database gets a unique db_version associated with it. This has some practical impacts on syncing transaction. We do not retain the history of modifications that have occurred on the database nor do we keep an event log. This means that we only keep current state around. Deltas between two databases can be computed by only exchanging Lamport timestamps.The amount of storage required should be a constant factor of the size of the base data, no matter how long a peer is offline.Writes to CRRs should be no slower than 2.5x a write to a normal SQLite table.

How CR-SQLite Transactions Work Today How CR-SQLite Transactions Work TodayĬr-sqlite started with a few foundational decisions: