Repodb.Stream

repodb · API reference

type config = {
  batch_size : int;
  max_rows : int option;
}

Streaming and collection helpers for row-oriented query results.

The streaming facade wraps driver row iteration in folds and iterators. Use it for large result sets when building all rows in memory is unnecessary, or when a backend supports cursor-style fetching.

module Stream = Repodb.Stream.Make (Repodb_postgresql.Driver)

  let count_active conn =
    Stream.fold conn "SELECT id FROM users WHERE active = $1"
      ~params:[| Driver.Value.bool true |]
      ~init:0
      ~f:(fun count _row -> count + 1)

cursor_fold and cursor_iter declare a cursor and fetch batches according to config. They are useful for PostgreSQL-style cursors; for drivers that materialize rows internally, they still provide a uniform API but do not reduce backend memory usage.

Sync and Seq provide small utility functions over already-materialized row lists or sequences. They are convenience helpers for tests and simple data processing; they do not perform database IO.

val default_config : config

module type STREAM = sig ... end

module Make
  (D : Driver.S) : 
  STREAM with type connection = D.connection and type error = D.error

module Sync : sig ... end

module Seq : sig ... end

val fold_raw : 
  query_fold:('a -> init:'b -> f:'c -> 'd) ->
  sql:'a ->
  init:'b ->
  f:'c ->
  'd

val iter_raw : query_iter:('a -> f:'b -> 'c) -> sql:'a -> f:'b -> 'c