Max limit for pickerFieldCustom

Below points might improve the performance while dealing with large DataSubSet;
1. In the 'suggestFunction' a condition something like 'Hit DB only if the character count in the search string is greater than or equal to a fixed number' (say 3). This reduces the number of records that return from DB as it uses more characters to match. When the character count is less than 3, return an empty array and include a message something like 'Type in atleast 3 character to search' for 'instructions' attribute of the picker field.
2. Indexing the column in DB which is used to compare might improve the performance.

is there is an option access the search string in pickerfieldcustom

is there is an option access the search string in pickerfieldcustom