Search by '.' causes non-selective query exception

Question

I have a simple query in an Apex trigger:

SELECT Id, Name FROM Account WHERE Name in :Names

where :Names is a set of strings

Set<String> Names = new Set<String>();

This query fails with System.QueryException: Non-selective query against large object type (more than 100000 rows) when the set contains '.' string.

Names.add( '.' );

Can anyone explain this behavior? Does the dot character have a special meaning in SOQL?

By the way, the account record with the weird name "." exists if this is important.

Update. There are more than 100000 accounts, most of them are unique. I can select the accounts using Developer Console:

As you can see, 2 records are selected. The exception rises when I try to reproduce the query in a trigger. I've created the most simple trigger that causes the exception:

trigger testTrigg on Contact (after insert) {
    Account[] accounts = [select Id, Name from Account where Name in ('.') limit 100];
}

Then I tried to create a contact and got the exception:

As I see, I get a different query plan depends on value of searching. '.' value is surprisingly equal to NULL.

Answer 1

I have tried in Developer Console, and there is no issue with the dot character.

Code

 Set<String> Names = new Set<String>();
 Names.add( '.' );
 List<Account> accounts = [SELECT Id, Name FROM Account WHERE Name in :Names];
 System.debug('hola ' + accounts);

Result

Let me share my thoughts about your issue

1. If you really have more than 100000 Account records with the name ".", there is a big issue in your design. Check if that is what you really want and remove / update those which name could be different.
2. If you don't have such a big amount of Accounts with "." as name, but you are not sure what is going on, try to run your query in the developer console and debug it. If you still get this issue, add a limit in order to retrieve less records and don't hit the issue. Maybe there is information that you don't know.

 [SELECT Id, Name FROM Account WHERE Name in :Names LIMIT 100];

3. If you have so many records with this name, but you only want to retrieve some of them, you can always add another filter. Actually Salefsorce advice is to filter by a indexed field, for instance ExternalIds one. And if your field is requires to be indexed, you can make a request. However that is not your issue as you are filtering by Name Standard field that is already indexed.