| bdt.eval {big.data.table} | R Documentation |
Main engine for passing queries to nodes, control parallelization, rbinding or simplifing returned object. Allows to measure timing and verbose messages.
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))
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. |
The 'bdt.eval.log' function is wrapper on 'bdt.eval' with 'logR()' call, so use only when logR connected.
Depending on *simplify, rbind* the results of evaluated expression.