Welcome to the Esri Forums. It's generally best to try searching on the content of your question before adding a new one. For example, a search on "maximum length" in the lower search box above ("Search Forums" from Geodatabase & ArcSDE) returned eight threads (not including yours) and two of them had the information Nidhin provided.
Reading other posts also provides feedback on how to write a good question. You should make sure to specify which version (and service pack) of ArcGIS software you are using in every query. Here in Geodatabase & ArcSDE, we'll also need to know which database you're using (database product and exact release or service pack).