dzitkowskik / mini-dos

Project for Distributed Operating Systems at Warsaw University of Technology (Mathematics and Computer Science department) Winter 2015
Apache License 2.0
0 stars 0 forks source link

Node - Select in in-memory db #44

Closed dzitkowskik closed 8 years ago

dzitkowskik commented 8 years ago

When node gets select, it should create inmemory db and create there tables needed for executing that query. It require issue #43 so it must be done first. Next node should get needed tables from all nodes that have this data (get infro where data is from master - issue #45) - here a method in node must be implemented to execute that selec * from selects.

(*) this is the point of this issue (2 and 3)

Select process will look like that:

  1. Get create table statements from master for needed tables
  2. Create them in in memory database (*)
  3. Execute selects (select * from table) in all nodes pointed by master (these which contain that data) for all needed tables (*)
  4. Serialize somehow ResultSets and send it to coordinating node
  5. Coordinating node inserts (unserialized data) to created tables in in memory db performing distinct on our internal id
  6. Perform sql query (our SELECT from client) on in memory db, then return result