In TIBCO Data Virtualization, properties to push LTRIM function to the underlying Oracle data source are not present which results in the query to fail with following error:

"Cannot push selectable because the data source Oracle does not support the function ~LTRIM"

There are two ways to resolve this error. 

Method 1: 
Add the following property in the oracle.capabilities file located at "[TDV_Server_Install_dir]\apps\dlm\cis_ds_oracle\conf\" 
LTRIM(~string,~string): LTRIM($1,$2). Save the file and restart the TDV Server Services for the changes to take effect.

Note: If current TDV instance is on a hotfixed version, copy the function to the oracle<TDV_version><Hotfix_version>.capability file present at the same path location. 

Method 2: 
To retain the changes when installing hotfixes or patches, add the below block in the values.xml file located at [TDV_Server_Install_dir]\conf\adapters\systems\[Oracle_version_adapter]\[Oracle_version_file]". Save the file and restart the TDV Server Services for the changes to take effect.

<common:attribute xmlns:common="http://www.compositesw.com/services/system/util/common">
  <common:name>/custom/LTRIM(~string,~string)</common:name>
  <common:type>STRING</common:type>
  <common:value>LTRIM($1,$2)</common:value>
  <common:configID>LTRIM(~string,~string)</common:configID>
</common:attribute>