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Cache configuration of database file pages, query programs, query results

Are there some possibilities to configure following caches in order to keep cache data for only some important entity types and for the entire life cycle of the EntityManagerFactory. Cache of database file pages. Cache of query programs. Cache of query execution results. btc_es BTC EmbeddedSystems

Query problem after transaction commit

to it. The client program can connect to the server and query to get all the records. However, after transaction ... _Connection: connecting 02> Test_Connection: connected 03> UI: start query [query for all object Goods ... = % 06> UI: end query 07> UI: start printing result 08> code= A, desc= Good A, byUser= test 09> code

IN expression in a Criteria Query

, it is written that ObjectDB is 100% compatible with JPA. However, I have problem with this JPQL query ... .employeeEntity = e) ORDER BY e.name with Hibernate, there was no problem with this query, but ObjectDB throws exception: com.objectdb.o.UserException: Unexpected query token 'EXISTS' Second problem

Logical Operators in JPQL and Criteria API

Logical operators in JPQL and in JPA criteria queries enable composition of complex JPQL boolean ... , the JDO Query Language). ObjectDB supports both forms. Binary AND (&&) Operator The following query ... The following query retrieves countries whose population or area exceeds a specified limit: SELECT c FROM

Comparison in JPQL and Criteria API

Most JPQL queries use at least one comparison operator in their WHERE clause. Comparison Operators ... , the JDO Query Language). ObjectDB supports both forms. Besides the different notation ... can be compared by using any comparison operator. Equality operators (=, <>, ==, !=) on strings in queries

queries more than 10 times slower using 2.8.1 versus 2.7.6

not do any statistics generate, just tried to use the new version - our reference query that takes ... . It seems that running your query on your sample database with version 2.8.1 is slower if statistics is not ... more performance lose with this query, there is a good chance that the same applies to your newer database

queries under 2.7.6_4 significantly slower than under 2.7.6

indicating deep query plan checks and an overall significant performance loss in all queries ... since version 2.7.6 that could possibly effect query execution. Could you please explain or post some of these logs that show deep query plan checks (and are new in 2.7.6_04)? In addition


a subquery root correlated to a root of the enclosing query. Create a subquery root correlated to a root of the enclosing query. Parameters: parentRoot - a root of the containing query Returns: subquery ... correlated to a join object of the enclosing query. Create a subquery join object correlated to a join object

[ODB1] Chapter 4 - JDO Metadata

of a class (including or excluding instances of subclasses) as well as execution of queries ... are not included in the extents of their classes, so they cannot be queried directly ... only in index declarations, as explained in the next section. 4.5 Index Definition Querying a large


application components. It is the factory for Query and Transaction instances, and contains methods ... of instances in the data store that might be iterated or given to a Query. The Extent itself might not ... of the specified Class Since: JDO 1.0 See Also: Query FetchGroup getFetchGroup(Class cls, String name

Getting Started

ObjectDB is very easy to use. Follow the Getting Started Tutorial and the Quick Tour manual chapter and in minutes you may be able to write and run first Java programs against ObjectDB.

Prior knowledge or experience in database programming (SQL, JDBC, ORM, JPA, etc.) is not required, but some background in using the Java language is essential.

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