当在 Hive 中创建表之后，第一次启动 impala-shell 时，请先执行 INVALIDATE METADATA 语句以便 Impala 识别出新创建的表(在 Impala 1.2 及以上版本，你只需要在一个节点上运行 INVALIDATE METADATA ，而不是在所有的 Impala 节点上运行)。
你也可以添加一些其他参数，查看有哪些参数：
#impala-shell -h Usage: impala_shell.py [options] Options: -h, --help show this help message and exit -i IMPALAD, --impalad=IMPALAD <host:port> of impalad to connect to [default: bd-dev-hadoop-70:21000] -q QUERY, --query=QUERY Execute a query without the shell [default: none] -f QUERY_FILE, --query_file=QUERY_FILE Execute the queries in the query file, delimited by ; [default: none] -k, --kerberos Connect to a kerberized impalad [default: False] -o OUTPUT_FILE, --output_file=OUTPUT_FILE If set, query results are written to the given file. Results from multiple semicolon-terminated queries will be appended to the same file [default: none] -B, --delimited Output rows in delimited mode [default: False] --print_header Print column names in delimited mode when pretty- printed. [default: False] --output_delimiter=OUTPUT_DELIMITER Field delimiter to use for output in delimited mode [default: t] -s KERBEROS_SERVICE_NAME, --kerberos_service_name=KERBEROS_SERVICE_NAME Service name of a kerberized impalad [default: impala] -V, --verbose Verbose output [default: True] -p, --show_profiles Always display query profiles after execution [default: False] --quiet Disable verbose output [default: False] -v, --version Print version information [default: False] -c, --ignore_query_failure Continue on query failure [default: False] -r, --refresh_after_connect Refresh Impala catalog after connecting [default: False] -d DEFAULT_DB, --database=DEFAULT_DB Issues a use database command on startup [default: none] -l, --ldap Use LDAP to authenticate with Impala. Impala must be configured to allow LDAP authentication. [default: False] -u USER, --user=USER User to authenticate with. [default: root] --ssl Connect to Impala via SSL-secured connection [default: False] --ca_cert=CA_CERT Full path to certificate file used to authenticate Impala's SSL certificate. May either be a copy of Impala's certificate (for self-signed certs) or the certificate of a trusted third-party CA. If not set, but SSL is enabled, the shell will NOT verify Impala's server certificate [default: none] --config_file=CONFIG_FILE Specify the configuration file to load options. File must have case-sensitive '[impala]' header. Specifying this option within a config file will have no effect. Only specify this as a option in the commandline. [default: /root/.impalarc] --live_summary Print a query summary every 1s while the query is running. [default: False] --live_progress Print a query progress every 1s while the query is running. [default: False] --auth_creds_ok_in_clear If set, LDAP authentication may be used with an insecure connection to Impala. WARNING: Authentication credentials will therefore be sent unencrypted, and may be vulnerable to attack. [default: none]
