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How to create a memory leak in Java?
...'s a bad practice not to close, but it doesn't cause a leak. Unclosed java.sql.Connection is the same.
– bestsss
Jul 17 '11 at 18:38
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What is the difference between the Data Mapper, Table Data Gateway (Gateway), Data Access Object (DA
...underlying datastore, the emphasis in TableDataGateway is encapsulation of SQL operations over a single table (not necessarily in a datastore neutral/portable fashion).
– Pierce Hickey
May 10 '13 at 17:31
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MongoDB with redis
... results. A company well-known for running MongoDB and Redis (along with MySQL and Sphinx) is Craiglist. See this presentation from Jeremy Zawodny.
MongoDB is interesting for persistent, document oriented, data indexed in various ways. Redis is more interesting for volatile data, or latency sensiti...
Common programming mistakes for Clojure developers to avoid [closed]
...boolean java-bool) "Yes" "No").
I got burned by this with clojure.contrib.sql library that returns database boolean fields as java Boolean objects.
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Why do we need boxing and unboxing in C#?
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true - it shows up all the time in ADO.NET too - sql parameter values are all 'object's no matter what the real data type is
– Ray
Jan 21 '10 at 19:12
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MongoDB: Combine data from multiple collections into one..how?
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Doing unions in MongoDB in a 'SQL UNION' fashion is possible using aggregations along with lookups, in a single query. Here is an example I have tested that works with MongoDB 4.0:
// Create employees data for testing the union.
db.getCollection('employe...
Is Python strongly typed?
... Short, crisp and to the point answer
– sql_learner
yesterday
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Git vs Team Foundation Server [closed]
...ogy around -- imagine you need a serious relational database. You evaluate Sql Server, Oracle, and MS Access. You end up choosing Access because it has the nicest GUI, in spite of the fact that it can't scale, doesn't enforce referential integrity very well, etc. Branching and Merging are the absolu...
What is the difference between partitioning and bucketing a table in Hive ?
... querying the data. For example, in the above table, if we write the below sql, it need to scan all the records in the table which reduces the performance and increases the overhead.
select * from sales_table where product_id='P1'
To avoid full table scan and to read only the records related to p...
Simple explanation of MapReduce?
...taset can then be reduced to a scalar value.
So if you think of it like a SQL statement
SELECT SUM(salary)
FROM employees
WHERE salary > 1000
GROUP by deptname
We can use map to get our subset of employees with salary > 1000
which map emits to the barrier into group size buckets.
Reduce ...