hadoop - What is the intention of Sqoop options? -single --double munus difference? -

in given example: username followed 1 - --connect , --table other commands followed double -- intention of such sqoop options? should use single , double?

sqoop-import --connect jdbc:mysql://localhost:3306/db1 -username root -password password --table tablename --hive-table tablename --create-hive-table --hive-import --hive-home path/to/hive_home

1. list item

generic hadoop arguments preceded single dash character (-), whereas sqoop arguments start 2 dashes (--), unless single character arguments such -p.

generic hadoop command-line arguments supported are:
-conf <configuration file> specify application configuration file
-d <property=value> use value given property
-fs <local|namenode:port> specify namenode
-jt <local|jobtracker:port> specify job tracker
-files <comma separated list of files> specify comma separated files copied map reduce cluster
-libjars <comma separated list of jars> specify comma separated jar files include in classpath.
-archives <comma separated list of archives> specify comma separated archives unarchived on compute machines.

fyi: must supply generic hadoop arguments -conf, -d, , on after tool name before tool-specific arguments (such --connect).