Sanne Grinovero ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) *created* an issue Hibernate ORM ( https://hibernate.atlassian.net/browse/HHH?atlOrigin=eyJpIjoiYzdhY2RlNTQz... ) / Task ( https://hibernate.atlassian.net/browse/HHH-15568?atlOrigin=eyJpIjoiYzdhY2... ) HHH-15568 ( https://hibernate.atlassian.net/browse/HHH-15568?atlOrigin=eyJpIjoiYzdhY2... ) Improve performance of runtime metamodel lookups by entity name ( https://hibernate.atlassian.net/browse/HHH-15568?atlOrigin=eyJpIjoiYzdhY2... ) Issue Type: Task Assignee: Unassigned Created: 01/Oct/2022 14:05 PM Labels: performance Priority: Major Reporter: Sanne Grinovero ( https://hibernate.atlassian.net/secure/ViewProfile.jspa?accountId=557058%... ) The class MappingMetamodelImpl is extremely hot during load, as a frequent operation is to lookup EntityPersister based on entity name (a String). Same for collection’s persisters. This is currently implemented using a ConcurrentHashMap , but I suspect could be optimised further by taking advantage of the fact that we know all valid entity names after boot: normally CHM is optimised for some balance of read and write operations, but we effectively need an immutable data structure which is optimised for read operations: write operations can be expensive as we’d compute the optimal data structure just once. A simple idea could be to sort the strings, and then implement some form of binary search; this theory is untested though - we should experiment. ( https://hibernate.atlassian.net/browse/HHH-15568#add-comment?atlOrigin=ey... ) Add Comment ( https://hibernate.atlassian.net/browse/HHH-15568#add-comment?atlOrigin=ey... ) Get Jira notifications on your phone! Download the Jira Cloud app for Android ( https://play.google.com/store/apps/details?id=com.atlassian.android.jira.... ) or iOS ( https://itunes.apple.com/app/apple-store/id1006972087?pt=696495&ct=Em... ) This message was sent by Atlassian Jira (v1001.0.0-SNAPSHOT#100207- sha1:ee9e30a )