Known Issues, Limitations, and Changes to Default Behavior

Following are known issues, limitations, and changes to default behavior in the OmniSci Platform.

OmniSci Core

ALTER TABLE ADD COLUMN does not work with geo column type

ALTER TABLE ADD COLUMN for a geo column type in MapD 4.1 only partially adds the column. Any queries on that column will result in a system failure. If you encounter this issue, contact MapD support at support@mapd.com.

MapD 4.0 backward compatibility with MapD 3.x

MapD 4.0 includes several major changes that can affect compatibility with 3.x releases.

ImportantMapD recommends you make a backup of your 3.x installations before proceeding with the upgrade to MapD 4.0 so that you can revert if the upgrade is unsuccessful or problematic.

For assistance during the upgrade process, contact MapD support at support@omnisci.com before you upgrade your system.

Migration from releases 3.2.1, 3.2.2, or 3.2.3

There is a known issue with automatic migration if the source database was migrated through any of the following releases: 3.2.1, 3.2.2 or 3.2.3. Contact OmniSci support before you update to v4.0.0 if you think this is the case with your database.

Object permissions and role-based access control on by default in MapD 4.0

If you are using MapD 3.x, setting up MapD 4.0 over an existing 3.x installation data directory migrates existing users and databases to use the new model automatically.

If you encounter issues during upgrade, you must restore your 3.x installation data from backup. Back up your 3.x installations before upgrading to MapD 4.0. You cannot downgrade MapD 4.0 data directories to use them in MapD 3.x installations.

Possible integer overflow on select count(*) for tables with more than 2^32 rows

To prevent return of negative counts, set bigint-count = true in mapd.conf.

Minimum supported NVIDIA driver version

The minimum supported NVIDIA driver version for MapD 4.0 is 384.81. Use the `nvidia-smi` utility included with the drivers to see the current active driver version. If you need assistance upgrading the driver, contact OmniSci support at support@omnisci.com.

Disable Error-correcting Memory before GPU installation

If you are using a server with an NVIDIA Tesla K80 card, you must turn off Error-correcting Code Memory (ecc) before you install OmniSci.

To disable Error-correcting Code Memory

  1. Open a terminal window on your host machine.
  2. Run the following command:
    sudo nvidia-smi --ecc-config=0
  3. Reboot your host machine

For more information, see:
NVIDIA-SMI documentation
https://www.nvidia.com/en-us/data-center/tesla-k80/
https://developer.nvidia.com/cuda-downloads

DELETE works only on tables created using MapD 4.0

DELETE functionality does not work on tables created using MapD 3.x. For DELETE to function correctly, create a new table in MapD 4.0 with the same schema, and then copy the data.

NOTE: To remove all rows from a table, use TRUNCATE TABLE instead of DELETE * FROM <table>.

UPDATE limitations

  • MapD does not currently support UPDATE from a subquery. For example, the following will not work:

    UPDATE tempDataView SET marks = ( SELECT marks FROM tempData b WHERE tempDataView.Name = b.Name )

  • UPDATE is not currently supported on variable-length data types.

MapD Rendering Engine

MapD 3.x shapefiles must be reimported for MapD 4.0

If you imported shapefiles into MapD 3.x, you must reimport this data in MapD 4.0 to use the new storage model for geospatial data types. Identify the tables you need to reimport and do so before using MapD 4.0.

Migrate custom client polygon rendering and hit-testing for MapD 4.0

If you imported polygon data into MapD 3.x for a custom application and are rendering or performing hit-testing on that data, upgrading to OmniSci 4.0+ will break your client-side polygon code because the storage model is different. For guidelines on migrating your code for OmniSci 4.0, see Migrating Polygon Rendering and Hit-testing for Custom Clients Upgrading to OmniSci 4.0+.

MapD Immerse

Dashboard sharing limitations

  • In MapD 4.0, dashboards can be shared only as ‘read-only’. Users with whom a dashboard has been shared cannot currently make edits to the dashboard.
  • For security reasons, dashboard sharing does not automatically provide permissions on underlying tables/views. For now, this requires a one-time setup by a superuser/administrative to configure a group of users or a role with permissions on the underlying objects.
  • Dashboard sharing does not currently work in MapD Cloud because each MapD Cloud user currently has a dedicated MapD instance. This limitation will be addressed in a future release.

Dashboards loaded by ID instead of name

If your MapD instance is set up to autoload specific dashboards on login by specifying the name in servers.json, you need to update the entry to use the dashboard ID instead. If you do not, your dashboards will not autoload. Find the dashboard ID by running `\dash` from mapdql, and then update the servers.json entry accordingly:

[
   {
     "database": "mapd",
     "master": "true",
     "username": "user",
     "password": "HyperInteractive",
     "url": "http://webserver.com:9092",
     "loadDashboard": "740",
     "GTM": "GTM-MDD8888"
   }
]

Immerse backward compatibility

MapD Immerse versions 3.4.0 and higher work only with MapD Core versions 3.4.0 and higher.

Unexpected update queries for Line and Histogram charts

Any update on Line or Histogram charts also starts an update query for range chart that is not required.

Unexpected render of complex data fields exported to CSV format

Binned columns and date extracts appear as JSON strings when exported to CSV format.

Multiple issues with Heatmap/Choropleth map legend

When using a Heatmap or Choropleth you might encounter these anomalies:

  • You cannot input more than one digit.
  • You can input a value lower than the minimum.
  • Min and Max can have the same value.

Adding layers in the Pointmap chart does not work when using Firefox browser

Sorting by non-grouped column in a table chart might not work properly in a distributed configuration

Old share links no longer load and render immediately.

Old share links (for example, https://www.mapd.com/demos/ships/#/link/mapd/228ae04e) no longer load and render all charts immediately. You must resize the browser or otherwise cause the page to re-render to see all charts.