first {SparkR}R Documentation

Return the first row of a SparkDataFrame


Aggregate function: returns the first value in a group.


first(x, ...)

## S4 method for signature 'SparkDataFrame'

## S4 method for signature 'characterOrColumn'
first(x, na.rm = FALSE)



a SparkDataFrame or a column used in aggregation function.


further arguments to be passed to or from other methods.


a logical value indicating whether NA values should be stripped before the computation proceeds.


The function by default returns the first values it sees. It will return the first non-missing value it sees when na.rm is set to true. If all values are missing, then NA is returned. Note: the function is non-deterministic because its results depends on order of rows which may be non-deterministic after a shuffle.


first(SparkDataFrame) since 1.4.0

first(characterOrColumn) since 1.4.0

See Also

Other SparkDataFrame functions: SparkDataFrame-class, agg(), alias(), arrange(),, attach,SparkDataFrame-method, broadcast(), cache(), checkpoint(), coalesce(), collect(), colnames(), coltypes(), createOrReplaceTempView(), crossJoin(), cube(), dapplyCollect(), dapply(), describe(), dim(), distinct(), dropDuplicates(), dropna(), drop(), dtypes(), exceptAll(), except(), explain(), filter(), gapplyCollect(), gapply(), getNumPartitions(), group_by(), head(), hint(), histogram(), insertInto(), intersectAll(), intersect(), isLocal(), isStreaming(), join(), limit(), localCheckpoint(), merge(), mutate(), ncol(), nrow(), persist(), printSchema(), randomSplit(), rbind(), rename(), repartitionByRange(), repartition(), rollup(), sample(), saveAsTable(), schema(), selectExpr(), select(), showDF(), show(), storageLevel(), str(), subset(), summary(), take(), toJSON(), unionByName(), union(), unpersist(), withColumn(), withWatermark(), with(), write.df(), write.jdbc(), write.json(), write.orc(), write.parquet(),, write.text()

Other aggregate functions: avg(), column_aggregate_functions, corr(), count(), cov(), last()


## Not run: 
##D sparkR.session()
##D path <- "path/to/file.json"
##D df <- read.json(path)
##D first(df)
## End(Not run)
## Not run: 
##D first(df$c)
##D first(df$c, TRUE)
## End(Not run)

[Package SparkR version 2.4.7 Index]