Non-continuous t-values?

General
1

Is it to be expected that t-values from a Log.txRange(fromT, toT) can be non-continuous (ex 1650, 1651, 1653…)?

1 Like
2

In the test below I would expect the last t to be 1002:

package datomic.samples;

import datomic.Connection;
import datomic.Peer;

import java.util.concurrent.ExecutionException;

import static datomic.Peer.tempid;
import static datomic.Util.list;
import static datomic.Util.map;

public class Test {

    public static void main(String[] args) throws ExecutionException, InterruptedException {

        String uri = "datomic:mem://localhost:4334/test";
        Peer.createDatabase(uri);
        Connection conn = Peer.connect(uri);

        conn.transact(list(map(
                ":db/ident", ":ns/attr",
                ":db/valueType", ":db.type/long",
                ":db/cardinality", ":db.cardinality/one"))).get();

        System.out.println(conn.db().basisT()); // 1000

        conn.transact(list(map(":db/id", tempid(":db.part/user"), ":ns/attr", 1))).get();
        System.out.println(conn.db().basisT()); // 1001

        conn.transact(list(map(":db/id", tempid(":db.part/user"), ":ns/attr", 2))).get();
        System.out.println(conn.db().basisT()); // 1003 - expected 1002
    }
}
3

My bad. Documentation makes no guarantees of a continuous series of t values. Only “consistent succession”:

A point in time in a database. Every transaction is assigned a numeric t value greater than any previous t in the database, and all processes see a consistent succession of ts. A transaction value t can be converted to a tx id with Peer.toTx.