Problems executing huge SQL statements

[daniel-kullmann]

Hello, I get the following error when trying to execute huge SQL statements (the statement string is 144k large):

Execute error: { [Error: error while parsing protocol: invalid communication buffer structure]
  message: 'error while parsing protocol: invalid communication buffer structure',
  code: 1033,
  sqlState: 'HY000',
  level: 1,
  position: 0 }

The SQL is large due to around 11000 string constants that are put into a hierarchy expression, so it can't be formulated differently (e.g. with a join).

When I reduce the SQL statement to around 126k (using only 5100 string constants), it works and I get the data back.

Is this a limit in the DB server, or does it come from node-hdb?

[holgerkoser]

The limitation comes from the MAX_PACKET_SIZE constant which is currently set to 131072 bytes.

You can modify the MAX_PACKET_SIZE in lib/protocol/common/Constants.js before you load the hdb module the first time.

// modify MAX_PACKET_SIZE before you load module hdb
require('hdb/lib/protocol/common/Constants').MAX_PACKET_SIZE = Math.pow(2,18);
var hdb = require('hdb');

[holgerkoser]

I have tested the proposal to modify the MAX_PACKET_SIZE above. It allows you to adapt it to your needs.