PreparedStatement is faster in Java, how db to do it?

Question

I know that PreparedStatement is faster than Statement in Java.

I do not know how oracle db server does this.

PreparedStatement gets precompiled. In the database server -> less work. This reduces the load on the database.

String sql = "SELECT * FROM users u WHERE u.id = ?";
PreparedStatement pstmt = connenction.prepareStatement(sql);
pstmt.setLong(1, userId);
pstmt.executeQuery();

Is the query cached on the database server and compiled only once?
If so, how does the database server know that this query was executed before?
How long has it been cached?

Answer 1

Is the query cached on the database server and compiled only once?

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// WRONG! Don't do it like this!
String sql = "SELECT * FROM users u WHERE u.id = "+userId;
PreparedStatement pstmt = connenction.prepareStatement(sql);

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Answer 2

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Answer 3

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