I defer to @Vitek's answer to the OP's question:
OData itself doesn't limit the length of the Url
But if others who arrive here because of IIS limitations : The request filtering module is configured to deny a request where the query string is too long.
, they may benefit from my answer. Follow that error's instructions:
Verify the configuration/system.webServer/security/requestFiltering/requestLimits@maxQueryString setting in the applicationhost.config or web.config file.
Follow the instructions:
<configuration>
<system.webServer>
<security>
<requestFiltering>
<requestLimits maxQueryString="50000">
</requestLimits>
...
You may also get this error:
The length of the query string for this request exceeds the configured maxQueryStringLength value.
This technique is described here and here, and it looks like this:
<configuration>
<system.web>
<httpRuntime maxQueryStringLength = "50000" ... />