Back to blogging after a gap of 8 months. I have been working on some cool optimization stuff related to Hibernate. Here is a brief summary of the best practices i have come across on this and past assignments involving Hibernate.
| # | Practice | What? | Why? | How? |
| 1 | Use Lazy Load | Don’t load objects until you need to use them. | Queries involve lesser joins, so become faster | By Using @Lazy annotation for simple attributes and LazyCollection for Collections |
| 2 | Use allocationSize>1 for Sequences | Use an allocationSize value of 50 or 100 instead of the default allocationSize of 1 | Avoids frequent db access to fetch next sequence value | By using @allocationSize=50, Hibernate will generate the next sequence values for 50 invocations before hitting the db again. |
| 3 | Keep big character/byte fields in a seperate entity | Seperate big fields like blob, clob, varchar(500), etc., into a seperate entity called <enityName>Details | Avoids time spent in fetching data for these fields on listing screens which do not typically display this information | By using a one-to-one mapping with the details object and keeping the direction of association from main->detail |
| 4 | Use Hibernate Caching | Using Hibernate Second Level cache and Query cache to store frequently used objects/results | Avoids hitting the db for frequently used information | Turn on Hibernate Second level cache and Quey cache |
Tags: Application Development, Hibernate, ORM, Performance