# Transactions

GetAll, SetAll and ExecAll are the foundation of transactions at key value level in immudb. They allow the execution of a group of commands in a single step, with two important guarantees:

  • All the commands in a transaction are serialized and executed sequentially. No request issued by another client can ever interrupt the execution of a transaction. This guarantees that the commands are executed as a single isolated operation.
  • Either all of the commands are processed, or none are, so the transaction is also atomic.

# SetAll

A more versatile atomic multi set operation

SetBatch and GetBatch example

# ExecAll

ExecAll allows multiple insertions at once. The difference is that it is possible to specify a list of mixes of key/value sets, references and zAdd insertions. The argument of a ExecAll is an array of the following types:

  • Op_Kv: ordinary key value item
  • Op_ZAdd: ZAdd option element
  • Op_Ref: Reference option element

It's possible to persist and reference items that are already persisted on disk. In that case is mandatory to provide the index of the referenced item. This has to be done for:

  • Op_ZAdd
  • Op_Ref If zAdd or reference is not yet persisted on disk it's possible to add it as a regular key value and the reference is done only. In that case if BoundRef is true the reference is bounded to the current transaction values.

# TxScan

TxScan permits iterating over transactions.

The argument of a TxScan is an array of the following types:

  • InitialTx: initial transaction id
  • Limit: number of transactions returned
  • Desc: order of returned transacations

# Filter Transactions

The transaction entries are generated by writing key-value pairs, referencing keys, associating scores to key-value pairs (with ZAdd operation), and by mapping SQL data model into key-value model.

With TxScan or TxByIDWithSpec operations it's possible to retrieve entries of certain types, either retrieving the digest of the value assigned to the key (EntryTypeAction_ONLY_DIGEST), the raw value (EntryTypeAction_RAW_VALUE) or the structured value (EntryTypeAction_RESOLVE).