Release Notes 2019.2.1

  • 250 bugs fixed. Thanks to all of our customers and an unprecedented number of deployments for helping us find and fix these!

  • Improved Unicode text handling on the GPU

  • Improved logging and monitoring of statements

  • Alibaba DataX connector


  • We’ve updated the show_server_status() function to more accurately reflect the status of statements across the cluster:

    • Preparing – Initial validation

    • In queue – Waiting for execution

    • Initializing – Pre-execution processing

    • Executing – statement is running

  • We’ve improved our log files and have unified them into a single file per worker, per date. Each message type has a unique code which can help identify potential issues. See the documentation for full details on the changes to the log structures.

  • WITH ADMIN OPTION added in GRANT/REVOKE operations, allowing roles to grant their own permissions to others.

  • HA cluster fully supports qualified hostnames, and no longer requires explicit IP addresses.

  • SQream DB CLI’s history can be disabled, by passing ./ClientCmd --no-history

Behaviour Changes

  • SQream DB no longer applies an implicit cast from a long text column to a shorter text column (VARCHAR/TEXT). This means some INSERT/COPY operations will now error instead of truncating the text. This is intended to prevent accidental truncation of text columns. If you want the old truncation behaviour, you can use the SUBSTRING function to truncate the text.


  • The client-server protocol has been updated to support a wider range of encodings. End users are required to use only the latest ClientCmd, JDBC, and ODBC drivers delivered with this version.

  • Clients such as SecureCRT and other shells must have locale set as cp874 or equivalent

  • When upgrading from SQream DB v3.2 or lower, the storage version must be upgraded using the upgrade_storage utility: ./bin/upgrade_storage /path/to/storage/sqreamdb/

Known Issues and Limitations

  • TEXT columns cannot be used as a GROUP BY key when there are multiple COUNT (DISTINCT …) operations in a query

  • TEXT columns cannot be used in a statement containing window functions

  • TEXT is not supported as a join key

  • The following functions are not supported on TEXT column types: chr, min, max, patindex, to_binary, to_hex, rlike, regexp_count, regexp_instr, regexp_substr

  • SQream Dashboard: Only works with a HA clustered installation

  • SQream Editor: External tables and UDFs don’t appear in the DB Tree but do appear in the relevant sqream_catalog entries.


250 bugs and issues fixed, including:

  • Variety of performance improvements:

  • Improved performance of TEXT by up to 315% for a variety of scenarios, including COPY FROM, INNER JOIN, LEFT JOIN.

  • Improved load performance from previous versions

  • Faster compilation times for very complex queries

  • DWLM:

    • Fixed situation where queries were not distributed correctly among all available workers

    • Fixed cannot execute - reconnectDb error error

    • Fixed occasional hanging statement

    • Fixed occasional Connection refused

  • Window functions:

    • Fixed window function edge-case error WindowA with no functions

    • Fixed situations where the SUM window function is applied on a column, partitioned by a second, and sorted by a third would return wrong results when scanning very large datasets

  • Other bugs:

    • Fixed situation where many concurrent statements running would result in map::at appearing

    • Fixed situation where SQream DB would restart when force-stopping an INSERT over the network

    • Fixed situation where RAM wasn’t released immediately after statement has been executed

    • Fixed Type doesn’t have a fixed size error that appeared when using an external table joined with a standard SQream DB table