Streaming table reads

    To read an entire table snapshot, use the readtable subcommand. Data is transferred as a stream, which enables you to read any size table.

    Read data:

    ydb table readtable episodes \
      --ordered \
      --limit 5 \
      --columns series_id,season_id,episode_id,title
    

    Where:

    • --ordered: Order read entries by key.
    • --limit: Limit the number of entries to read.
    • --columns: Columns whose values should be read (all by default) in CSV format.

    Result:

    ┌───────────┬───────────┬────────────┬───────────────────────────────┐
    | series_id | season_id | episode_id | title                         |
    ├───────────┼───────────┼────────────┼───────────────────────────────┤
    | 1         | 1         | 1          | "Yesterday's Jam"             |
    ├───────────┼───────────┼────────────┼───────────────────────────────┤
    | 1         | 1         | 2          | "Calamity Jen"                |
    ├───────────┼───────────┼────────────┼───────────────────────────────┤
    | 1         | 1         | 3          | "Fifty-Fifty"                 |
    ├───────────┼───────────┼────────────┼───────────────────────────────┤
    | 1         | 1         | 4          | "The Red Door"                |
    ├───────────┼───────────┼────────────┼───────────────────────────────┤
    | 1         | 1         | 5          | "The Haunting of Bill Crouse" |
    └───────────┴───────────┴────────────┴───────────────────────────────┘
    

    To only get the number of read entries, use the --count-only parameter:

    ydb table readtable episodes \
      --columns series_id \
      --count-only
    

    Result:

    70