DataMind Oda saves every chat as a log file on your computer, and each file carries the version of the log format that wrote it. This page explains how Oda opens a chat written by another version, what it changes when it does, and the messages it shows when it cannot. For where these files live and how they are kept, see Chat logs on disk; for what a log contains, see Chat log format.
Oda starts with the file's first line, the header. It names the format version, so Oda can sort the file before reading the chat inside it. There are four cases:
corrupt session log: with the reason; for the message you meet, see Chat log problems.An older chat needs no preparation from you: Oda converts it as it opens.
Opening a chat to read it changes nothing on disk. The updated copy is written only when the chat next records something new. Oda then:
The original file stays as it was: same name, same folder, same contents. A chat can have several generations of its log side by side; the newest is the chat's current state, and the earlier ones stay as they are. For the file names and the folder layout, see Chat logs on disk.
Some files cannot be read by this copy of Oda. Oda refuses them rather than guess, because reading a file it does not fully understand could show the wrong history. A refusal is the same every time you try; nothing is written and no new file is saved.
A refusal is not damage. Nothing about the file changes, and a copy of Oda that can read its format can still open it.
The message names the reason:
session "<id>" uses log format v<version>, but this version of DataMind Oda reads only v<current>: the log was written by a newer version — update DataMind Oda to open it. Update DataMind Oda, then open the chat again.session "<id>" uses log format v<version>, older than the supported v<current>, and this build ships no upgrade path for it. The file is kept as it is.session "<id>" contains event type "<type>" (seq <n>) unknown to this version of DataMind Oda and not marked ignorable; refusing to interpret the log — it was likely written by a newer version. Update DataMind Oda, or open the file in the version of Oda that wrote it.When a conversion stops part-way through, the message says the file was left alone: source v<version> artifact remains unchanged (raw log: <path>). The path names the file on your computer.
Oda never converts a chat down to an older version, and it never falls back to an earlier readable generation: if the newest file cannot be read, it is refused, not replaced by a different history.
The format has been through five versions, numbered v0 to v4. Current DataMind Oda writes v4 and converts files from v0 through v3 as it opens them.
The version sits in the file's first line, so Oda knows it before the chat itself is read.
What an update changes, one version at a time:
No conversion adds or removes anything you wrote; it rearranges how records are stored.
The first line of a log file is the header, and it carries the format version. Oda reads it before anything else, so it can tell how to treat the file without reading the chat inside. The header's fields are on Chat log format.
Only when the chat next records something new. Opening a chat to read it saves nothing; the updated copy is prepared, checked and saved as a new file beside the original at the next write. Until then nothing on disk changes.
Not usually. A refusal can mean that this copy of Oda cannot read the file's format, that the file comes from a newer version, or that it contains an event this copy does not know. The file is kept as it was. A damaged file is a different case: the message reports what could not be read; see Chat log problems.
Current DataMind Oda writes v4 and converts files from v0 through v3 as it opens them. A file written in a newer format than your copy is refused, with the update direction in the message.
Update DataMind Oda when the message says the file was written by a newer version or contains an unknown event; updating is the fix. For any other refusal, keep the file and the message for your DataMind OS administrator. Trying again without changing anything gives the same refusal.
The file is left alone: nothing is written and no new file is saved, and the message says so with source v<version> artifact remains unchanged (raw log: <path>). Trying again repeats the refusal in the same way.
No. Oda reads the version from the file and converts the chat as it opens it. There is no separate step for you.
The file stays as it was, so a copy of Oda that can read its format opens it. A file from a newer version opens in the newer copy; Oda never converts a chat down to an older version.