Writing Hive table from Spark specifying CSV as the format -


i'm having issue writing hive table spark. following code works fine; can write table (which defaults parquet format) , read in hive:

df.write.mode('overwrite').saveastable("db.table")  hive> describe table; ok val           string time taken: 0.021 seconds, fetched: 1 row(s)

however, if specify format should csv:

df.write.mode('overwrite').format('csv').saveastable("db.table")

then can save table, hive doesn't recognize schema:

hive> describe table; ok col                     array<string>           deserializer time taken: 0.02 seconds, fetched: 1 row(s)

it's worth noting can create hive table manually , insertinto it:

spark.sql("create table db.table(val string)") df.select('val').write.mode("overwrite").insertinto("db.table")

doing so, hive seems recognize schema. that's clunky , can't figure way automate schema string anyway.

that because hive serde not support csv default.

if insist on using csv format, creating table below:

create table my_table(a string, b string, ...) row format serde 'org.apache.hadoop.hive.serde2.opencsvserde' serdeproperties (    "separatorchar" = "\t",    "quotechar"     = "'",    "escapechar"    = "\\" )   stored textfile;

and insert data through df.write.insertinto

for more info:

https://cwiki.apache.org/confluence/display/hive/csv+serde


Comments

Post a Comment

Popular posts from this blog

PHP and MySQL WP -

i trying accomplish 2 things here code. writing php directly wp page using insert php plugin. 1) query mysql database , return results 1 column 4 columns. 2) make each result own hyperlink directs user new wp page runs new query on page. i able query show results , turn results dynamic hyperlink, cannot formatting down. right returns result 1 column. here have: [insert_php] $servername = "localhost"; $username = "login"; //edited privacy $password = "password"; //edited privacy $database = "database"; //edited privacy // create connection $conn = new mysqli($servername, $username, $password, $database); // check connection if ($conn->connect_error) { die("connection failed: " . $conn->connect_error); } echo "connected successfully"; //get results database $result = mysqli_query($conn,"select mine mines order mine"); $all_property = array(); //declare array saving property //showing proper...
Read more

android - InAppBilling registering BroadcastReceiver in AndroidManifest -

i'm implementing inapp billing in android app. works well, however, i'm trying decouple broadcast receiver activity manifest. suggestion in android's trivialdrive sample: // important: dynamically register broadcast messages updated purchases. // register receiver here instead of <receiver> in manifest // because call getpurchases() @ startup, therefore can ignore // broadcasts sent while app isn't running. // note: registering listener in activity bad idea, done here // because sample. regardless, receiver must registered after // iabhelper setup, before first call getpurchases(). currently there's class extends broadcastreceiver : public class iabbroadcastreceiver extends broadcastreceiver { /** * intent action receiver should filter for. */ public static final string action = "com.android.vending.billing.purchases_updated"; private final iabbroadcastlistener mlistener; public iabbroadcastreceiver(iabbroadcastlistener listener) { m...
Read more

nginx - phpPgAdmin - log in works but I have to login again after clicking on any links -

i have setup postgres 9.6 , phppgadmin on centos 7 server nginx, i can log in phppgadmin, postgresql server on right of page remains crossed out , link try browse (databases, roles etc) requires log in again. i'm thinking seems sessions problem, unsure how resolve it. any pointers on how fix or should looking @ in order track down problem? solved. turns out owner of /var/lib/php/session apache - needed nginx. sorted changing ownership nginx below: chown -r nginx:nginx /var/lib/php/session/
Read more