bdt.eval: big.data.table evaluate on nodes

Description Usage Arguments Details Value

View source: R/big.data.table.R

Description

Main engine for passing queries to nodes, control parallelization, rbinding or simplifing returned object. Allows to measure timing and verbose messages.

Usage

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bdt.eval(x, expr, lazy = TRUE, send = FALSE, simplify = TRUE,
  rbind = TRUE, parallel = TRUE, silent = TRUE, outer.aggregate = FALSE,
  .log = getOption("bigdatatable.log", FALSE))

bdt.eval.log(x, expr, lazy = TRUE, send = FALSE, simplify = TRUE,
  rbind = TRUE, parallel = TRUE, silent = TRUE, outer.aggregate = FALSE,
  .log = getOption("bigdatatable.log", FALSE))

Arguments

x

big.data.table.

expr

expression.

lazy

logical if TRUE then *expr* is substituted.

send

logical, if TRUE submit expression appended with 'TRUE' to not fetch potentially big results from provided *expr*, useful for data.table *set** or ':=' functions.

simplify

logical if *TRUE* (default) it will simplify list of 1 length same type objects to vector.

rbind

logical if *TRUE* (default) results are data.table they will be rbinded.

parallel

logical if parallel *TRUE* (default) it will send expression to nodes using 'wait=FALSE' and collect results afterward executing each node in parallel.

silent

should be silently catched by 'try' or 'logR' if enabled.

outer.aggregate

logical or a function, if *TRUE* will able the same query to rbind of results from each node, should not be used with '.SD', '.N', etc. Also conflicts with filtering in 'i'. Can be also a function taking first argument 'x' rbinded data.table.

.log

logical if *TRUE* then logging will be done using logR to postgres db.

Details

The 'bdt.eval.log' function is wrapper on 'bdt.eval' with 'logR()' call, so use only when logR connected.

Value

Depending on *simplify, rbind* the results of evaluated expression.


jangorecki/big.data.table documentation built on May 18, 2019, 12:24 p.m.