I am trying to represent a relation (table) in C++ code: The columns of the relation are integers. The number of columns in the relation is fixed at runtime. No duplicates should be allowed (this is the major source of cost). I want to have a map from names to relations. Any ideas for an efficient implementation, the main issue here is detecting duplicates at insertion time, it can be very costly.

Reputation: 3171

Representing relations in C++

I am trying to represent a relation (table) in C++ code:

The columns of the relation are integers.
The number of columns in the relation is fixed at runtime.
No duplicates should be allowed (this is the major source of cost).
I want to have a map from names to relations.

Any ideas for an efficient implementation, the main issue here is detecting duplicates at insertion time, it can be very costly.

Upvotes: 2

Answers (2)

Björn Pollex

Reputation: 76788

KennyTM has a point. You could use SQLite. As described in the link, you can use it to create a temporary in-memory database.

Upvotes: 0

kennytm

Reputation: 523214

Make each row of the table a struct Row.

Use a std::set or std::unordered_set to store these structs. Collision (querying) can be detected in (for std::set) O(log n + d) time or (for std::unordered_set) amortized O(d) time where d is the number of columns.

To efficiently map from names to rows, create a boost::bimap<std::string, Row>.

Upvotes: 1

Representing relations in C++

Answers (2)

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