When you run a SELECT COUNT(*), the speed of the results depends a lot on the structure & settings of the database. I am interested in database name, table name and row count, To automate this, you can make a small bash script and some bash commands. Should I say "sent by post" or "sent by a post"? if [ $lc -eq 1 ]; then For example, we want to find all the DB.TABLE_NAME where we have a column named “country”. In one of the explain clauses, it shows row counts like below: The benefit is that you are not actually spending cluster resources to get that information. echo "FAIL" Although there is no documentation in the official wiki, you can … See the below query for getting record count. Here are a few ways of listing all the tables that exist in a database together with the number of rows they contain. The HQL command is explain select * from table_name; but when not optimized not shows rows in the TableScan. Is Acts 15:28 evidence that the Holy Spirit is a personal being capable of having opinions about things? Hive cost based optimizer make use of these statistics to create optimal execution plan. To automate this, you can make a small bash script and some bash commands. Even though there is nolock hint used it still has to do lots of work just get the rowcount. Below is the example of computing statistics on Hive tables: Links: Since EXTERNAL table doesn't delete the data and you are loading file again you are getting the count difference. By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. The COMPUTE STATS statement always gathers statistics about all columns, as well as overall table statistics. Massive overfit during resnet50 transfer learning, Wait for bash background jobs in script to be finished, Server http:/localhost:8080 requires a user name and a password. I need for all the views. hive count rows in partition, For a partitioned Hive table (stored as ORC), I can count the rows in a partition very quickly with a query like this, presumably because Hive gets the count directly from table statistics: select count(*) from db.table where partition_date = '12-01-2015' Solved: For a partitioned Hive table (stored as ORC), I can count the rows in a partition very quickly with a query like this, presumably because. What crime is hiring someone to kill you and then killing the hitman? I have a query(ex: below) for which I want to get the statistics like how many rows it results, what Hive - Get number of rows, total size resulted in a query Detailed Table Information | Table(tableName:tableex5, is given in the analyze statement, statistics for all partitions are computed. This is quite straightforward for a single table, but quickly gets tedious if there are a lot of tables, and also can be slow. If I ask my doctor to order a blood test, can they refuse? How to deal with incompetent PhD student as an undergrad. First run, This stores all tables in the database in a text file tables.txt. What would happen if 250 nuclear weapons were detonated within Owens Valley in California? The notation COUNT( column_name ) only considers rows where the columnÂ. How to get view count of rows from metadata. When you use a particular schema and then issue the SHOW TABLES command, Drillreturns the tables and views within that schema. hive> select txn_id,msg_id from pa_lane_txn limit 10;​Â. Here, we are setting the short name A for getting table name and short name B for getting row count. ]view_name [(column_name [COMMENT column_comment], ...) ] It is better to practice, and generally more efficient to explicitly list the column names that you want to be returned. [ Faster than count (*) ] count (col_name) : output = total number of entries in the column "col_name" excluding null values. I don't want to run "select count(*) from " from the. hive> SELECT ROW_NUMBER() OVER( ORDER BY ID) as ROWNUM, ID, NAME FROM sample_test_tab; rownum id name 1 1 AAA 2 2 BBB 3 3 CCC 4 4 DDD 5 5 EEE 6 6 FFF Time taken: 4.047 seconds, Fetched: 6 row(s) Do not provide any PARTITION BY clause as you will be considering all records as single partition for ROW_NUMBER function . How estimate row count of a PostgreSQL view? To get the number of rows in a single table we usually use SELECT COUNT(*) or SELECT COUNT_BIG(*). How can I get row count from all tables using hive. Usually, it depends on … table row count from hive metastore, As of the HDP 2.6.1 release here is a query that I use to find row counts on a specific partitioned table: SELECT * FROM hive.PARTITION_PARAMS AS A, hive.PARTITIONS AS B WHERE A.PARAM_KEY='numRows' and A.PART_ID=B.PART_ID and A.PART_ID IN ( SELECT PART_ID FROM hive.PARTITIONS WHERE TBL_ID=(SELECT A.TBL_ID FROM hive.TBLS AS A, hive.DBS AS B WHERE A.DB_ID=B.DB_ID AND B.NAME='DATABASE_NAME' AND A Hi, is it possible to find out the number of rows in a table from the hive metastore? rev 2021.3.17.38813, Stack Overflow works best with JavaScript enabled, Where developers & technologists share private knowledge with coworkers, Programming & related technical career opportunities, Recruit tech talent & build your employer brand, Reach developers & technologists worldwide. How to install Django Rest Framework using Anaconda? SELECT user_id,user_name,timestamp FROM ( SELECT user_id,user_name,timestamp,row_number() over (partition by userid order by timestamp desc) as visit_number from user) user_table WHERE visit_number = 1 Here, we are using join sys.objects with sys.partitions from sys.partitions, we can get row count of table and sys.objects will return the name of a schema (table name). A rhythmic comparison, Limit exists with definition but not with polar coordinates. Join Stack Overflow to learn, share knowledge, and build your career. How do I create the left to right CRT refresh effect with material nodes? share. The query takes the sum of total size of all the Hive tables based on the statistics of the tables. Get row count from all tables in hive, You will need to do a select count(*) from table. To display all the data stored in a table, you will use the select * from command followed by the table name. There are two solutions:[crayon-604ef8e091df4850201151/]Get the delimiter of a Hive … echo "PASS" And for non-partitioned tables, “tblproperties” will give the size: To get all the properties: show tblproperties yourTableName. The most crucial piece of data in all the statistics is the number of rows in the table (for an unpartitioned or partitioned table) and for each partition (for a partitioned table). You can collect the statistics on the table by using Hive ANALAYZE command. To automate this, you can make a small bash script and some bash commands. Getting the row count from each table one by one and comparing and consolidating the results can be a tedious task. How to filter lines in two files where the value in a specific column has the same sign (- or +)? How to randomly sample from a Scala list or array? if you are on your own to do all operation like load, analysis, drop etc, Hive support the INTERNAL table as well. How to find the least common multiple of a range of numbers? How do I mention the specific database that it needs to refer in below snippet: hive count(*), I want to count values similar in a map where key would be the value in the Hive table column and the corresponding value is the count. the “input format” and “output format”. First, we can use case statements to transpose required rows to columns. A much faster way to get approximate count of all rows in a table is to run explain on the table. how to find the table row count in hive query using group by, Hive count number of matching rows in another table, Fetching distinct combination of column values and their count in Hive, Different row count while creating a table or view in Impala, Row Count Zero in Hive Metastore for table ingested using Sqoop.
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