Count distinct value hive Follow answered Jan 12, 2018 at 4:34. If you want to consider empty strings same as null, you can use COUNT(DISTINCT NULLIF(TRIM(c), '')) instead of COUNT(DISTINCT c). DC1 and DC2 should be equal. Th reason why SELECT * works and SELECT COUNT(*) doesn't is that latter involves a MR job. rstackhouse. sql import functions as F, Window # Function to calculate number of seconds from number of days days = lambda i: i * 86400 # Create some test data df = spark. By default, it's true for all 3. Improve this answer. How to count distinct values in a node in XSLT? Example: I want to count the number of existing countries in Country nodes, in this case, it would be 3. Let's consider an example where you have a "customers" table with a column named "customer_id" that stores unique identifiers for each customer. SELECT COUNT(*) FROM (SELECT DISTINCT A FROM TAB_X) I fail to understand exactly why it is so. select count When we use COUNT and DISTINCT together, Hive always ignores the setting such as mapred. This is my understanding of how these queries would be converted to the map reduce behind the scene. Improve this question. In this case hive can return the results by performing an hdfs operation. krokodilko krokodilko. Hive count distinct UDAF2. To find the unique values in the cell range A2 through A5, use the following formula: Mapper is totaly depend on number of file i. Share. show() 1. Modified 8 years, Im trying to select distinct values from each column inside a given table. It applies to all columns you list in your select clause. count distinct values from multiple column hive. DROP TABLE IF EXISTS Each mapper emits one value, the count. When the number of distinct values in col is smaller than B, this gives an exact percentile value As of Hive 4. The function works with various data types, such as numeric, text, or dates/times. 2. header. id>=0 and t1. This works in a similar way as the distinct count because all the ties, the records with the same value, receive the same rank value, so the biggest value will be the same as the distinct count. Here's how my table looks like: SELECT user (seqnum = 1) over (partition by user_id order by order_date) as running_distinct_count from (select et. Optimize your data analysis process and efficiently explore and e. memory. product; df. Counting columns with a where clause. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Visit the blog The use of union guarantees distinct values - union removes duplicates, This query will out-perform all other answers, because the database can efficiently count distinct values within a table much faster than from the unioned list. Super I need to count the number of null values for each column in the table grouped by date. Split is noting but the logical split of data. My Query is lacking performance due to the creation of many MapReduce Jobs and im looking for a better solution. data. hadoop; hive; shoud be COUNT(product_code) Also I am running Hive-0. Distinct(). distinct value count: the number of distinct values. This is rather a hadoop related thing than hive. You can create a script that will count distinct items in the active range. step 1: create a temp table with the duplicate record list inserted, using insert and select like so: CREATE TABLE #Temp( product_Name Char( 30 ), Date Date, CustomerID int ); INSERT INTO #temp (product_Name, Date, CustomerID) select x. COUNT in COUNT OVER PARTITION SQL Server. count(expr)– Returns the total number of rows for expression excluding null. in your case that would be the 1,1 for b=1 (because 1 is minimum of 1 and 5). If I don't do an operation on Basically I'm trying to get a count of distinct elements from *col2 and col3 combined* and group them against col1. i am trying to aggregate a data using "state,count( distinct val ) group by state " but want just the "Not Null" Val - String datatype. [Date] as dateX, x. map. NDV is an aggregate function that returns an approximate value similar to the result of COUNT(DISTINCT col), the “number of distinct values. SELECT * FROM (SELECT BODY_TYPE, CITY, COUNT(DISTINCT BODY_TYPE) AS TOTAL_FOR_BODY, count(DISTINCT expression) counts only each distinct occurrence of a value expression evaluates to. When combined, COUNT and DISTINCT can be used to count the number of unique values in a column or a set of columns. I want to count just the IDs that are unique to either category. 4-cdh) code optimization on MapReduce, in my project we have used lot of count distinct operation with groupby clause, an example hql is shown below. low value: the smallest value in the column. Count based on separate group by columns and with a condition. it will be helpfull for sure to the future users SQL/Hive count distinct column. Ask Question Asked 10 years, 10 months ago. Apache is a non-profit organization helping open-source software projects released under the Apache license and managed with open governance and privacy policy. Of course we do not want this for obvious reasons. Integration with Hive UDFs, UDAFs, and UDTFs; External user-defined scalar functions (UDFs) Function invocation; If DISTINCT is specified then the function returns the number of unique values which do not contain NULL. high value: the largest value in the column. from l in logins group l by l. DISTINCT keyword is used in SELECT statement in HIVE to fetch only unique rows. I'd suggest a 2 steps approach. – For each column, we use `select(column)` to select the column and `distinct(). 3,638 4 4 gold badges 21 21 silver badges 43 43 bronze badges. An alternative to the COUNT DISTINCT function is to use a combination of COUNT and GROUP BY. At least not in MySQL 5. Current implementation has the limitation that no ORDER BY or window specification can be supported in the partitioning clause for performance reason. Commented Sep 25, 2011 at 8:37. 479 seconds, Can you paste the output here for when you Counting distinct values for a given column partitioned by a window function, without using approx_count_distinct() 1 Combining COUNT DISTINCT with FILTER - Spark SQL The above formula will then return the distinct count of the values in the range B3:B12. sql. alias to true (the default is false). The COUNTIFS function counts the number of cells in a range that match one of the provided conditions. x versions. Learn how to retrieve and manipulate data from tables using basic SELECT statements, WHERE clauses, aggregation functions, DISTINCT keyword, JOIN operations, ORDER BY and LIMIT clauses, and more. hive sql adding record count as column. For Hive 0. 0. createDataFrame([(17, "2017-03 When I count the number of row I get . 27 8. It seems that the way F. functions import col import pyspark. You can use explode to output separate rows for each category and then count distinct to get the result you are looking for. name,x. id order by t1. Syntax; COUNTIFS (range1, criteria1, [range2], [criteria2], ) Arguments; range1: [required] This is the first range to be evaluated. formatter" property can be used to control the underlying formatter implementation and as a Distinct support in Hive 2. 0, HDP v2. e size of file we can call it as input splits. @akshaygvs, above query ignores NULL and doesn't count at all, but for an empty string, yes. try following query to get result : Add unique value in hive table. kindly check my The row_number Hive analytic function is used to assign unique values to each row or rows within group based on the column values used in OVER clause. 7. Count Distinct Values with Office Scripts. *, row_number() over (partition by user_id, product order by order_date) as seqnum from example _table et Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company Here's a solution I wrote that uses python: import os dictTabCnt={} print("=====Finding Tables=====") tableList = os. Select counts of occurrences. I would like to run a query on this to get a distinct count of the direct_lead_id when is_clicked = True. The implementation uses the dense version of the HyperLogLog++ (HLL++) algorithm, a state of the art cardinality estimation algorithm. range2: [optional] This is the second range to be evaluated. create table t(a int) insert into t values (1),(2),(3),(3) select count (distinct a) from t select distinct count (a) from t group by a It will give you 3 for first query and Select * from table, would be an example. I want to have EF core translate . It does not count each row. Distinct on specific column in Hive. one is client id and other is comma separated string with all unique item ids. Follow edited Jun 4, 2019 at 18:59. Hive The former means "select the count of distinct rows" and the latter means "select the distinct values of count(*)" (and there's only one value so it is semantically the same as select count(*) from test) Share. Just the bigger you get, the higher the count of these duplicate rows! hive> select key,count(*)cnt from default. mb to some higher value. In Impala, we can specify NDV(column). HIVE/HiveQL Get Max count. I have a hive table with IDs and two categories. count distinct values from This will count only the distinct values for that column. id_congestion, congestion. Ask Question Asked 8 years, 10 months ago. We are counting the rows, so we can use DENSE_RANK to achieve the same result, extracting the last value in the end, we can use a MAX for that. See upcoming Apache Events. Select(x=>x. distinct(). I've attached two different queries that should both result in 7 unique items purchased. For Hive 2. select x, max(y) from table1 group by x Equally you could use avg() or min() 2) OR, you could collect all the values of y in a list: select x, collect_set(y) from table1 group by x This will give you: x|y 1|2,3,4 2|2 3|1,2 Here, it has counted the total no. Counting unique (distinct) users per day. /* Be sure to use DISTINCT in the outer query to de-dup */ SELECT DISTINCT MyTable. of rows based on the partitioned by the department and assigned the value to each row. Hot Network Questions Dissect shape into as few pieces as possible that can be reassembled into a square I am getting two very different numbers for these seemingly similar queries on (hive) tables: select count(*) from test # result: 2609173 select distinct count(*) from test # result: 2609173 insert into testToo select distinct * from test # result: inserted 673065 rows Any recommendations on how I might be able to discern what is Read More SQL: Distinct and One way to do it is with a self join as distinct isn't supported in window functions. optimize. "count(expr) - Returns the number of rows for which the supplied expression is non-NULL; count(DISTINCT expr[, expr]) - Returns the number of rows for which the supplied expression(s) are unique and non-NULL. Again SQL Server will use the tiny index on the view and avoid the table scan on the big table. But once we do a select distinct columnname from tableabc we get the header back!. Count distinct each column in Hive. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company I'm looking for a formula calculating : distinct Count + multiple criteria Countifs() does it but do not includes distinct count Here is an example. It is much faster than the combination of COUNT and DISTINCT, and uses a constant amount of memory and thus is less memory-intensive for columns with high cardinality. select count(*) from (select user from some_table group by user) q; This query has two stages. Modified 10 years, id date value 1 01-01-2014 10 1 03-01-2014 05 1 07-01-2014 40 1 05-01-2014 20 2 05-01-2014 10 SUMMARY : count (*) : output = total number of records in the table including null values. countDistinct("a","b","c")). Learn the syntax of the count aggregate function of the SQL language in Databricks SQL and Databricks Runtime. count()` to get the count of distinct values. product = p. Find Unique Count Postgresql query into hivesql. count(DISTINCT expr[, expr]) – Returns the count of distinct rows of expression (or expressions) excluding null values. I now want to create a new column based on this one, but now with arrays that have only the unique strings of the arrays in column1. First get count for both the tables C1 and C2. Apache Hive is a data warehouse product based on Hadoop. id<=5 --change this number per requirements group by t1. dummy_data group by key order by cnt desc limit 10; --ordering desc and limiting 10. How to combine split and count in hive. , count(DISTINCT u) , count(CASE WHEN plat=1 THEN u ELSE NULL END) , count(DISTINCT CASE WHEN plat=1 If you want to consider empty strings same as null, you can use COUNT(DISTINCT NULLIF(TRIM(c), '')) instead of COUNT(DISTINCT c). Date into g select new { Date = g. Date | email -----+----- 1/1/12 | [email protected How to deal with hive? Thank you. ID name phone 1 John 602-230-4040 2 Brian 602-230-3030 3 John 602-230-4040 4 Brian 602-230-3030 -- list all the column names SELECT COLUMN_NAME FROM INFORMATION_SCHEMA. You need to segment, or group by, art in order to count how many records have each unique value of art. C1 and C2 can be obtained from the following query. count"="1"). from pyspark. count() 2. It counts the "Count unique values in a range", using CountIF as a tool. @ErwinBrandstetter – user4672728. The DISTINCT keyword is used to return only distinct (unique) values. 100 200 300 500 600 hadoop; hive; Hive - Select unique rows based on some key field. id Get Counts of Distinct Values into single row Hive. 11. For a group, generate a map with key from a secondary column counting the distinct values from keys from a third one. rewrite . – We iterate through each column of the DataFrame with a `for` loop. Without grouping it will be just one line with total count. On stage 1 the GROUP BY aggregates the users on the map side and emits one value for each user. Finally, thanks to the sponsors who donate to the Apache Foundation. line. A collection of Hive UDFs. select query, count_distinct_map(country, HIVE : counting null values based on group by Labels: Labels: Apache Hive; arunak. It's the result I except, the 2 last rows are identical but the first one is distinct (because of the null value) from the 2 others. Applies to: Databricks SQL Databricks Runtime Returns the estimated number of distinct values in expr within the group. My Hive table: 'dynpart' with columns: Id, Name, Technology. How can I rewrite the count function to count distinct values? sql-server; count; window-functions; Share. For example, if the range of values contains Here is how you would accomplish this: create a view that returns the distinct [month] [year] values and then index [year] [month] on the view. date = d. dup, x. Select distinct on specific columns but select other columns also in hive. 0 through 2. value; Share. count(DISTINCT expr[, expr]) Higher values yield better approximations, and the default is 10,000. Let's say I have a DB table with PersonID Skip to main content. popen("hive --outputformat=dsv --showHeader=false I have a hive table with 300 columns (mixed datatype), I want to check what percentage of records have NULL values in all the columns. COLUMNS WHERE TABLE_NAME = 'table_name'; -- count the distinct values in a column SELECT COUNT(DISTINCT Col1) Col1 FROM table_name; -- tell if a column contains any Null SELECT (CASE WHEN (SUM(CASE WHEN Col1 IS NULL THEN 1 The COUNT(DISTINCT col) aggregation functions by default uses a variant of HyperLogLog, a fast approximate distinct counting algorithm. 33 2 2. Here is an example: UserID CityID CountryID TagID 100000 1 30 5 100001 1 30 6 100000 2 How to take distinct values in hive join. distinct. Distinct count in Cassandra. Hot Network Questions Keeping meat frozen outside in 20 degree weather I have a table such as the following FK_OrgId , FK_UserId 3 , 74 1 , 74 1 , 74 3 , 4 4 , 5 1 , 5 I'm trying to count FK_OrgId but I have to eliminate duplicates. Thanks to Ricardo Saporta who pointed this out to me here. – Scotty. I'm using the following code to agregate students per year. x, set hive. The set of statistics available for a particular query depends on the connector being used and can also vary by table. I want find duplicates in a table in Hive as shown below. I have a column in my hive db that contains arrays of strings, let's say column1. Add a comment | 2 . Remove DISTINCT from your COUNT() and add "GROUP BY art" at the end of your query. count(DISTINCT expr[, expr])– Returns the count of distinct rows of expression (or expressions) excluding null values. 6, HortonWorks Hadoop distribution. The purpose is to know the total number of student for each year. Hi Martin, I tried the following command : SELECT res, count(1) AS count FROM results where field='title' GROUP BY res LIMIT 20; but I got these results !! A = load 'myTestData' using PigStorage('\t') as (a1,a2,a3); user_list = foreach A GENERATE $2; unique_users = DISTINCT user_list; unique_users_group = GROUP unique_users ALL; uu_count = FOREACH unique_users_group GENERATE COUNT(unique_users); store uu_count into 'output'; Is there a better way to get count of **Counting Distinct Values**: – We initialize an empty dictionary `distinct_counts` to store the distinct counts. Follow edited Apr 12, 2018 at 20:59. I have a table in hive that looks something like this cust_id prod_id timestamp 1 11 2011-01-01 03:30:23 2 22 2011-01-01 03:34:53 1 22 2011-01-01 04:21:03 2 1) This will give you the max value of y for each value of x. It is quite reasonable that your table has only 151,616 distinct values in the column a, but multiple rows with the same value in the column a have different values in other columns. Query 1 - Only one stage - The mappers emit the Column A as the key and the value as 1. job. I have a mysql table- User Value A 1 A 12 A 3 B 4 B 3 B 1 C 1 C 1 C 8 D 34 D 1 E 1 F 1 G 56 G 1 H 1 H 3 C 3 F 3 E 3 G 3 I need to run a query which re The COUNTIFS Function. . e. Paul White Hive. I tried with a query as: select col1, count(distinct col2, col3) from dummy SELECT COUNT(DISTINCT A) FROM TAB_X; QUERY 2. Distinct count and group by in HIVE. Contribute to dataiku/dataiku-hive-udf development by creating an account on GitHub. 0 and later, columns can be specified by position when configured as follows:. select t1. functions as F df. So I was wondering how is this functionality implemented in Hive, is there a UDAFCountDistinct for this? And the answer: To achieve count distinct, Hive relies on the GenericUDAFCount. id_element ORDER BY congestion. hadoop fs -get, more or less. 2. Can it be done simply. As of Hive 4. You can optimize the performance of this using hive. Use an appropriate query style depending on what you want to achieve. select count(*) as c from mytable where master_id is not null c 1134041 Additionally, the master_id seems to be never null. I have marked the query with [] bracket where we feel we need to do some change. name, x. In SQL, the COUNT() function is used to count the number of rows that match a specified condition. The row does not mean entire row in the table but it means “row” as per column listed in the SELECT statement. * from yourTable t1 join ( select accountNum, date, status, time,count(distinct action) from yourTable where action in ('B', 'S') group by accountNum, 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. So the result for above example would be: a=X | count ----- a=2 | 2 a=4 | 2 How can I do this? sql; hive; Share. answered Apr 12, 2018 at 20:57. Office scripts are another way to get a distinct count for a selected range. – Vincent. For PySPark; I come from an R/Pandas background, so I'm actually finding Spark Dataframes a little easier to work with. Data in original table: Client Id Item Ids 1 1,2,3,4 2 3,4,6,8 4 4,5,1,3 2 3,4,7,8 3 5,6,8,2 4 7,8,9,4 An aggregate function that returns an approximate value similar to the result of COUNT(DISTINCT col), the "number of distinct values". Syntax: COUNT([DISTINCT | ALL] expression) [OVER (analytic_clause)] Depending on the argument, COUNT() considers rows that meet certain conditions: The notation COUNT(*) includes NULL values in the total. date and t. For example, the Hive connector does not currently provide statistics on data size. you have to use the analyze command before the count. 0, Hive offers a surrogate key UDF which you can use to generate unique values which will be far more performant than UUID strings. Commented Mar 30, 2021 at 10:51. Hive happens to support substring_index(), so you can do: count distinct values from multiple column hive. The row does not mean entire row in the table but it means “row” as per column listed in the SELECT Here’s how to do complex count statements to simplify queries. ” While in hive APPX_COUNT_DISTINCT Function implements the HyperLogLog algorithm for approximating the number of distinct elements in a multiset. Commented Feb 28, Count of unique values in a rolling date range for R. SELECTING DISTINCT PRODUCT AND DISPLAY COUNT PER PRODUCT for another answer about this type of question, this is my way of getting the count of product based on their product name using distinct. product group by d. An aggregate function that returns the number of rows, or the number of non-NULL rows. Hive DISTINCT() for all columns? 1. 8. 1. SELECT id, COUNT(DISTINCT(cat)) as Get Counts of Distinct Values into single row Hive. 0 and later, set hive. The Rank Hive analytic function is used to get rank of the rows Count distinct doesn't always give me the right answer. This question is tagged SQL Server, and this isn't SQL Server syntax Select distinct values from each column in Hive. CustomerID from ( SELECT Also, this window order is not display order, so this wont add any value i think. week_nb, congestion. Then all values have to be aggregated to produce the total count, and that is the job of one single reducer. 5. 0 the "hive. See following example. The result should be distinct values from this column of array which should be . tasks = 20 for the number I'm trying to obtain rolling number of unique values in a window. In the output it will display the count of unique values Hope this helps. I want to extract occurrences of "a=X", group by X and count rows for distinct values. date, p. In the two plans below, the aggregations part in the Output of Group By Operator of Map 1 are different. An example may make things more clear: SQL/Hive count distinct column. Count() into something like SELECT COUNT(DISTINCT property) Let's take an example. The IDs can be unique to a category or can belong to both categories. select count(*) from table1 if C1 and C2 are not equal, then the tables are not identical. Example: Counting Distinct Customers. Use cross join to generate the rows and then left join and group by for the calcualtion:. datetime. value, count(*) from count_unique group by x. Tx!! Willem Make partitioned set smaller, up to the point there is no duplicates over counted field : SELECT congestion. frame(table(dummyData))[,2] posted in a comment to Chase's answer. You can do that by following. How to do a row wise count in It does not give you the count of distinct values in conjunction of two columns. Aggregate functions can also be used with the DISTINCT keyword to do aggregation on unique values. How do I best go about this in HiveQL? I've looked around but haven't found a solution I can implement. groupby. This may be useful if you need to feed the counts of unique values into another function, and is shorter and more idiomatic than the t(as. Considering below join condition is it possible to take only distinct key_col from table 2? i dont want to use select distinct * from select * from Table_1 a left join Table_2 b on a. HiveQL: Parse strings and count. date), COUNT(congestion. I need to take the distinct values from Table 2 while joining with Table 1 in Hive. countDistinct deals with the null value is not intuitive for me. id,count(distinct t2. NET. OTOH, GROUP BY, DISTINCT or DISTINCT ON treat NULL values as equal. Get Counts of Distinct Values into single row Hive. SQL: Sums over Combinations. countdistinct is true. Over partition by vs where conditions. Also it will not fetch DISTINCT value for SELECT col1, col2, COUNT(DISTINCT col3) FROM sometable WHERE col3 IN (1,2) GROUP BY col1, col2 HAVING COUNT(DISTINCT col3) > 1 If you actually want to return all of the records that meet your criteria you need to do a sub select and I'd like a running distinct count with a partition by year for the following data: DROP TABLE IF EXISTS #FACT; CREATE TABLE #FACT("Year" INT,"Month" INT, "Acc" varchar(5)); Microsoft SQL Query Get count of DISTINCT values using Over Partition. However in Hive 0. You can optimi Similar as other database engines, Hive provides a number of built-in aggregation functions for data analysis, including LEAD, LAG, FIRST_VALUE, LAST_VALUE, COUNT (w/ Aggregate functions can also be used with the DISTINCT keyword to do aggregation on unique values. Trying to count the unique bytes in a string? DATA but you are adding the values together. 13 and I could get the desired result by executing the following query select key,product_code, cost The SUM function adds numbers and the COUNTIF function counts those cells containing numbers that meet specific criteria. Noah Goodrich Noah Goodrich. my input is : name id a 2 a 3 a 4 b 1 c 4 c 4 d 7 d 9 my expected output i I think the solution is to actually 'collect_set' the users ( collect unique values) and take the size of the array, for small numbers of user ( ie. There seems to be a limitation regarding the use of expressions in the HAVING clause if they don't appear in the SELECT clause. Running these commands in order should give you the correct count: hive> ANALYZE TABLE daily_firstseen_analysis PARTITION(day) COMPUTE STATISTICS; hive> SELECT COUNT(*) FROM daily_firstseen_analysis; i. There might well be a lot of rows in which expression evaluates to the same value. port) as cnt from tbl t1 join tbl t2 on t1. Yes, Hive does support distinct on multiple columns. Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company 1. Im using Hive v0. Hive Script, DISTINCT with SUM. Id Name Technology 1 Abcd Hadoop 2 Efgh Java 3 Ijkl MainFrames 2 Efgh Java We have options like 'Distinct' to use in a select query, but a select query just retrieves data from the table. 2: Find distinct count for both the tables DC1 and DC2. Commented Jun 23, 2016 at 15:01. 0 and later (see HIVE-9534) Distinct is supported for aggregation functions including SUM, COUNT and AVG, which aggregate over the distinct values within each partition. 5. So, I want a result like I want one hive query which generate table with two column. – Michael Krelin - hacker Commented Aug 25, 2009 at 21:01. Based on the unique values of one column sum other Column in SQL. The sum() simply adds the two counts together. " Return:BIGINT count(*)– Returns the count of all rows in a table including rows containing NULL values. ; count (1) : output = total number of records in the table including null values. Hive/SQL count occurrences for multiple columns and rows. Count() }; For a side by side comparison to the original method syntax (which personally I like better) here you go Replace "column_name" with the actual column you want to count the distinct values of, and "table_name" with the name of the table where the column resides. Related. Distinct support in Hive 2. 0. But it's not a Countif with distinct count. A hive query can be a Map Reduce job. Paulo Campez. product, count(t. – Koushik Roy. I am trying to learn about deleting duplicate records from a Hive table. If you discover any security vulnerabilities, please report them privately. It will create two split means two blocks. Follow edited Aug 28, 2013 at 13:46. --Step 3: SELECT dt, cum_distinct_cnt FROM ( --Step 2: SELECT rid, dt, COUNT(CASE WHEN row_num = 1 THEN rid END) OVER (ORDER BY dt ROWS BETWEEN Unbounded PRECEDING AND CURRENT ROW) cum_distinct_cnt FROM ( --Step 1: SELECT rid, dt, ROW_NUMBER() OVER (PARTITION BY For a long time, UUIDs were your best bet for getting unique values in Hive. distinct count on hive does not match cardinality count on elasticsearch. What is your datasize? Try increasing the mapper heapsize by setting the property mapred. Login). Count Number of Columns In Hive. Similar as other database engines, Hive provides a number of built-in aggregation functions for data analysis, including LEAD, LAG, FIRST_VALUE, LAST_VALUE, COUNT (w/ or wo/ DISTINCT), SUM, MIN, MAX, AVG, RANK, ROW_NUMBER, DENSE_RANK, CUME_DIST, PERCENT_RANK, COUNT() function with distinct clause . answered Sep 26, 2008 at 19:54. Another aggregate like a count(1) or a Grouping sets like a ROLLUP/CUBE. – Distinct is a keyword, not a function. I think the only way of doing this in SQL-Server 2008R2 is to use a correlated subquery, or an outer apply: SELECT datekey, COALESCE(RunningTotal, 0) AS RunningTotal, COALESCE(RunningCount, 0) AS RunningCount, COALESCE(RunningDistinctCount, 0) AS RunningDistinctCount FROM document OUTER APPLY ( SELECT SUM(Amount) AS If you will include the BODY_TYPE in the GROUP BY then it will be grouped by BODY_TYPE and CITY so for each CITY and each BODYTYPE, you will get one row. SQL Query: Count Distinct with Condition. key_col approx_count_distinct aggregate function. kindly check my updated answer. answered Mar 2, Use a COUNT(DISTINCT Location) and join against a subquery on Type and Color The GROUP BY and HAVING clauses as you have attempted to use them will do the job. select x. You should remove BODYTYPE from the GROUP BY and SELECT list as follows:. 2,326 25 25 silver badges 29 29 bronze badges. 1. But as we want to group by PRODUCT_NAME also we donot know how to calculate the distinct occurance. id_element, ROW_NUMBER() OVER( PARTITION BY congestion. I'm not sure why you are using regexp_replace() rather than just replace(). distinct values from 2 tables. It enables users to count unique values within a specified column. The formulas count the values that appear only once, but don’t count the total number of actual unique values present there, considering all the values. Hive - Select unique rows based on some key field. hive> select * from dfr_distinct; OK 100000000938 5 7 12. select d. Because the table 2 has duplicate records. date) from (select distinct date from t) d cross join (select distinct product from t) p left join t on t. 75 4. To do this: Setup a Spark SQL context Since COUNT counts only not null values, you will get a number of NULLs in birthdate column. Count distinct doesn't always give me the right answer. 12. In HIve it is successfully executed but in impala In particular, using NDV() iinstead of COUNT(DISTINCT) is much faster, but returns approximate results only it will be great if you can give an hint in which impala version or cdh version this functionality may be valuable. for combination (customer1,product1) price for product1 is 25+20/2(no of distinct occurences for customer(1 and 3)) = 22. Hive - Given the following source data (say the table name is user_activity): +-----+-----+-----+ | user_id | user_type | some_date | +-----+-----+-----+ | 1 | a The one I gave as example gives you distinct b values and minimal a for each. Remember: NULL values won’t be taken into account when counting distinct values. functions as f In query syntax it looks like this note that there is no query syntax for Distinct and Count. how to do group by in HIVE. There are two things which prevent Hive from optimize multiple count distincts. There is no UDAF specifically implemented for count distinct. [ Faster than count (*) ] count (col_name) : output = total number of I am trying to count matches between columns resulting from an INNER JOIN of two tables on unique values of a single column in one of the two tables. C1 and C2 should be equal. orderby. reduce. select count(*) as c from mytable c 1129563 If I want to count the number of row with a non null master_id, I get a higher number. Case III: Count Employees with PARTITION BY department and ORDER BY salary DESC and windowing specification Explore the syntax and various types of SELECT queries in Apache Hive with this comprehensive guide. If we do a basic select like select * from tableabc we do not get back this header. hive count and count distinct not correct. Here a sample: List of Product : select * FROM Product Product Name Count Using Distinct : Below query can give required cumulative distinct count. My Query so far build is wrong in many levels, Group by cant with DISTINCT and also using Count(*) doesnt give me any results with Group my etc Get Counts of Distinct Values into single row Hive. Second Method import pyspark. You can still use this faster query with IS NOT DISTINCT FROM instead of = for any or all comparisons to make NULL compare equal. How to do a row wise count in Hive. 4. Ex: my file size is 150MB and my HDFS default block is 128MB. Hive has to ship the jar to hdfs, the jobtracker queues the tasks, the tasktracker execute the tasks, the final data is put into hdfs or shipped to the client. Type, MyTable. which would fit in memory) SELECT size( collect_set( user_id ) ) as uniques end_date, group FROM I'm looking for a smart way to count occurrences. How to add one column which is the count(*) from the table? 2. SELECT distinct col1, col2, col3 from TABLE If you want to select distinct rows, you can use * instead. Follow Hive unique string count. Key, Count = (from l in g select l. week_nb) -- remove distinct OVER( PARTITION BY Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand; OverflowAI GenAI features for Teams; OverflowAPI Train & fine-tune LLMs; Labs The future of collective knowledge sharing; About the company I ran into a Hive query calculating a count distinct without grouping, which runs very slow. position. I would be looking to get the date and count of distinct emails that we have between said date and 3 days ago. While query select distinct count(a) will give you list of unique counts of values in a. date, congestion. Commented Aug 19, 2019 at 20:27. It's definitely worth the upgrade to EF5 for this feature. Go to the Automate tab and select the New Script option. Original answer - exact distinct count (not an approximation) We can use a combination of size and collect_set to mimic the functionality of countDistinct over a window:. This query (based on your original query) works: select t1. Hot Network Questions Movie where crime solvers enter into criminal's mind Did the term "irrational number" initially have any derogatory intent? I am working on a hive(1. id-t2. Table looks like: hive count and count distinct not correct. g. Documentation is a bit sparse still but here is one example: In groupByExpression columns are specified by name, not by position number. SQL/Hive count distinct column. Did somebody else also have this issue? Your intuition is spot on, Hive just doesn't like counting distinct with windowing functions. 3. 060 2 8 0 Time taken: 0. Select multiple distinct rows. criteria1: [required] range1 criteria. Add a comment | Your Answer SQL/Hive count distinct column. sql; hive; hiveql; Share. ; The notation COUNT(column_name) only considers rows where the is not working properly when hive. **Is In some DBs this can be done using "select distinct on x,y from tabel" but hive dosent support "distinct on" – Tomer. Color, Location FROM MyTable INNER JOIN ( /* Joined subquery returns type,color pairs having Hope the below query helps you: select userid, MAX(CASE WHEN productid = 1 THEN count ELSE null END) as product1count, MAX(CASE WHEN productid = 2 THEN count ELSE null END) as product2count, MAX(CASE WHEN productid = 3 THEN count ELSE null END) as product3count from (Select user_id, product_id, count(*) from masampleinput group by I want to find the count(distinct column name) wihtout using group by in hive. unique_text count helll123 2 falst0 1 Basically, we will ignore prefixes and only count unique texts. First approach is to use following two queries: select count(*) from mytable; // this will give total row count I have a table in Hive that has 20 columns and I want to count unique records and all records per hour. Sahil Desai Sahil Desai. HIVE: Finding running total excluding duplicates. Commented Jan 10, 2022 at 14:30. key_col = b. We have a little problem with our tblproperties ("skip. property). agg(F. product order by d. Syntax: NDV([DISTINCT | ALL] expression [,scale]) I had the same problem, and using ANALYZE fixed it. 702 1 1 gold badge 8 8 silver badges 25 25 bronze badges. &lt;Artists_by_Countries&gt; &lt; Weird thing is it seems to produce 1,024 unique values no matter how many rows > 1000 that you generate. Add a SQL/Hive count distinct column. If the SELECT has 3 columns listed then SELECT DISTINCT will fetch unique row for those 3 column values only. date is a reserved word. – Anwar Shaikh. That might give you 513,238 distinct rows. Follow edited Mar 2, 2020 at 14:18. Count Distinct over partition by sql. Something like this. 36. [Product_name] as nameX , x. it is counted it as one of unique value. I would suggest the next solution, in case prod is just a column in the table and by "count(cust_id)" you want to count the number of occurrences per cust_id in the table: Below example explains the Hive count analytic function: select pat_id, dept_id, count(*) over (partition by dept_id order by dept_id asc) as pat_cnt from patient; The row_number Hive analytic function is used to assign unique values to each row or rows within group based on the column values used in OVER clause. hive counting same field many times. I want to find duplicate rows from one of the Hive table for which I was given two approaches. 1k 7 7 gold badges 59 Limitations of the COUNTIFS Function to Count Unique Values in Excel. When we use COUNT and DISTINCT together, Hive always ignores the setting such DISTINCT keyword is used in SELECT statement in HIVE to fetch only unique rows. rhcjqv mukap lbshe lyelbyn xllsi gjtun qpl yorpby bmzovu laxybm