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What is the difference between Non-Repeatable Read and Phantom Read?
What is the difference between non-repeatable read and phantom read?
9 Answers
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Explanation of JSONB introduced by PostgreSQL
...me operation at a json typed value)
When jsonb will be available with a stable release, there will be two major use cases, when you can easily select between them:
If you only work with the JSON representation in your application, PostgreSQL is only used to store & retrieve this representati...
java.net.ConnectException: Connection refused
...t also helped me, the test connection was succesfull but couldn't show any tables data.
– Damien Christophe
Aug 13 '19 at 7:52
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Find object by id in an array of JavaScript objects
...ore efficient, this is still a linear search, so if you want to use a hash table, see Aaron Digulla's answer (beware of impl. details).
– tne
Mar 12 '14 at 11:41
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Are foreign keys really necessary in a database design?
... code using things like ON DELETE CASCADE. This means that if you have one table containing users and another containing orders or something, then deleting a user could automatically delete all orders that point to that user.
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MongoDB Show all contents from all collections
...of your database.
db.stats()
step 5: listing out all the collections(tables).
show collections
step 6:print the data from a particular collection.
db.'collection_name'.find().pretty()
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The case against checked exceptions
...with it.
This would be clearer with a counter-case. Imagine I'm writing a table API. I have the table model somewhere with an API including this method:
public RowData getRowData(int row)
Now as an API programmer I know there will be cases where some client passes in a negative value for the ro...
Difference between @OneToMany and @ElementCollection?
...ring> strings;
Simpler, isn't it? Note that you can still control the table and column names using @CollectionTable annotation.
See also:
Java Persistence/ElementCollection
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what is the difference between OLE DB and ODBC data sources?
...nt times.
ODBC
ODBC is an industry-wide standard interface for accessing table-like data. It was primarily developed for databases and presents data in collections of records, each of which is grouped into a collection of fields. Each field has its own data type suitable to the type of data it con...
Why does my application spend 24% of its life doing a null check?
... other. With the GC heap compacting algorithm otherwise having an unpredictable affect on that. Best to not let me guess at this, measure so you know a fact.
– Hans Passant
May 15 '13 at 11:21
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