DISTINCT not supported in Stock Demo

Took the StockListDemo under pages and changed the subscription mode for the OverwriteTable to DISTINCT. When the page is loaded an alert tells me that "DISTINCT is not supported for item item1 code (24)".

The jsdoc for OverwriteTable shows that DISTINCT is supported for this table type, what else needs to be changed to use DISTINCT mode?

The problem you're facing is not client side and is not related to the table class you used.
There is a method in the MetadataProvider interface ( modeMayBeAllowed ) that lets you specify which subscription modes are admitted for a certain item.
(Moreover you can specify this setting on a per-user basis with the isModeAllowed method)

In the distributed StockListDemo adapter, the MetadataProvider implementation used is the LiteralBasedProvider. This class has not a fixed behaviour for the modeMayBeAllowed method but it can be configured within the adapters.xml file. The current configuration:

Code xml:

---

1. <param name="item_family_1">item.*</param>
2. <param name="modes_for_item_family_1">MERGE</param>

---

means that all items whose name matches the item.* pattern are only allowed in MERGE mode and all other items are not allowed in any mode.

Change MERGE with DISTINCT on the second line and restart the Server in order to perform your test. Note that no item should be allowed in both MERGE and DISTINCT mode.
The details of this simple configuration language are explained in
DOCS-SDKs\sdk_adapter_java\examples\Reusable_MetadataAd apters\javadoc\com\lightstreamer\adapters\metadata \LiteralBasedProvider.html