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• Big Data – Data Mining with Hive – What is Hive? – What is HiveQL (HQL)? – Day 15 of 21

  - by Pinal Dave

  In yesterday’s blog post we learned the importance of the operational database in Big Data Story. In this article we will understand what is Hive and HQL in Big Data Story. Yahoo started working on PIG (we will understand that in the next blog post) for their application deployment on Hadoop. The goal of Yahoo to manage their unstructured data. Similarly Facebook started deploying their warehouse solutions on Hadoop which has resulted in HIVE. The reason for going with HIVE is because the traditional warehousing solutions are getting very expensive. What is HIVE? Hive is a datawarehouseing infrastructure for Hadoop. The primary responsibility is to provide data summarization, query and analysis. It  supports analysis of large datasets stored in Hadoop’s HDFS as well as on the Amazon S3 filesystem. The best part of HIVE is that it supports SQL-Like access to structured data which is known as HiveQL (or HQL) as well as big data analysis with the help of MapReduce. Hive is not built to get a quick response to queries but it it is built for data mining applications. Data mining applications can take from several minutes to several hours to analysis the data and HIVE is primarily used there. HIVE Organization The data are organized in three different formats in HIVE. Tables: They are very similar to RDBMS tables and contains rows and tables. Hive is just layered over the Hadoop File System (HDFS), hence tables are directly mapped to directories of the filesystems. It also supports tables stored in other native file systems. Partitions: Hive tables can have more than one partition. They are mapped to subdirectories and file systems as well. Buckets: In Hive data may be divided into buckets. Buckets are stored as files in partition in the underlying file system. Hive also has metastore which stores all the metadata. It is a relational database containing various information related to Hive Schema (column types, owners, key-value data, statistics etc.). We can use MySQL database over here. What is HiveSQL (HQL)? Hive query language provides the basic SQL like operations. Here are few of the tasks which HQL can do easily. Create and manage tables and partitions Support various Relational, Arithmetic and Logical Operators Evaluate functions Download the contents of a table to a local directory or result of queries to HDFS directory Here is the example of the HQL Query: SELECT upper(name), salesprice FROM sales; SELECT category, count(1) FROM products GROUP BY category; When you look at the above query, you can see they are very similar to SQL like queries. Tomorrow In tomorrow’s blog post we will discuss about very important components of the Big Data Ecosystem – Pig. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Big Data, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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• SQL SERVER – UNION ALL and ORDER BY – How to Order Table Separately While Using UNION ALL

  - by pinaldave

  I often see developers trying following syntax while using ORDER BY. SELECT Columns FROM TABLE1 ORDER BY Columns UNION ALL SELECT Columns FROM TABLE2 ORDER BY Columns However the above query will return following error. Msg 156, Level 15, State 1, Line 5 Incorrect syntax near the keyword ‘ORDER’. It is not possible to use two different ORDER BY in the UNION statement. UNION returns single resultsetand as per the Logical Query Processing Phases. However, if your requirement is such that you want your top and bottom query of the UNION resultset independently sorted but in the same resultset you can add an additional static column and order by that column. Let us re-create the same scenario. First create two tables and populated with sample data. USE tempdb GO -- Create table CREATE TABLE t1 (ID INT, Col1 VARCHAR(100)); CREATE TABLE t2 (ID INT, Col1 VARCHAR(100)); GO -- Sample Data Build INSERT INTO t1 (ID, Col1) SELECT 1, 'Col1-t1' UNION ALL SELECT 2, 'Col2-t1' UNION ALL SELECT 3, 'Col3-t1'; INSERT INTO t2 (ID, Col1) SELECT 3, 'Col1-t2' UNION ALL SELECT 2, 'Col2-t2' UNION ALL SELECT 1, 'Col3-t2'; GO If we SELECT the data from both the table using UNION ALL . -- SELECT without ORDER BY SELECT ID, Col1 FROM t1 UNION ALL SELECT ID, Col1 FROM t2 GO We will get the data in following order. However, our requirement is to get data in following order. If we need data ordered by Column1 we can ORDER the resultset ordered by Column1. -- SELECT with ORDER BY SELECT ID, Col1 FROM t1 UNION ALL SELECT ID, Col1 FROM t2 ORDER BY ID GO Now to get the data in independently sorted in UNION ALL let us add additional column OrderKey and use ORDER BY  on that column. I think the description does not do proper justice let us see the example here. -- SELECT with ORDER BY - with ORDER KEY SELECT ID, Col1, 'id1' OrderKey FROM t1 UNION ALL SELECT ID, Col1, 'id2' OrderKey FROM t2 ORDER BY OrderKey, ID GO The above query will give the desired result. Now do not forget to clean up the database by running the following script. -- Clean up DROP TABLE t1; DROP TABLE t2; GO Here is the complete script used in this example. USE tempdb GO -- Create table CREATE TABLE t1 (ID INT, Col1 VARCHAR(100)); CREATE TABLE t2 (ID INT, Col1 VARCHAR(100)); GO -- Sample Data Build INSERT INTO t1 (ID, Col1) SELECT 1, 'Col1-t1' UNION ALL SELECT 2, 'Col2-t1' UNION ALL SELECT 3, 'Col3-t1'; INSERT INTO t2 (ID, Col1) SELECT 3, 'Col1-t2' UNION ALL SELECT 2, 'Col2-t2' UNION ALL SELECT 1, 'Col3-t2'; GO -- SELECT without ORDER BY SELECT ID, Col1 FROM t1 UNION ALL SELECT ID, Col1 FROM t2 GO -- SELECT with ORDER BY SELECT ID, Col1 FROM t1 UNION ALL SELECT ID, Col1 FROM t2 ORDER BY ID GO -- SELECT with ORDER BY - with ORDER KEY SELECT ID, Col1, 'id1' OrderKey FROM t1 UNION ALL SELECT ID, Col1, 'id2' OrderKey FROM t2 ORDER BY OrderKey, ID GO -- Clean up DROP TABLE t1; DROP TABLE t2; GO I am sure there are many more ways to achieve this, what method would you use if you have to face the similar situation? Reference: Pinal Dave (http://blog.sqlauthority.com)   Filed under: Best Practices, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Whether to use UNION or OR in SQL Server Queries

  - by Dinesh Asanka

  Recently I came across with an article on DB2 about using Union instead of OR. So I thought of carrying out a research on SQL Server on what scenarios UNION is optimal in and which scenarios OR would be best. I will analyze this with a few scenarios using samples taken  from the AdventureWorks database Sales.SalesOrderDetail table. Scenario 1: Selecting all columns So we are going to select all columns and you have a non-clustered index on the ProductID column. --Query 1 : OR SELECT * FROM Sales.SalesOrderDetail WHERE ProductID = 714 OR ProductID =709 OR ProductID =998 OR ProductID =875 OR ProductID =976 OR ProductID =874 --Query 2 : UNION SELECT * FROM Sales.SalesOrderDetail WHERE ProductID = 714 UNION SELECT * FROM Sales.SalesOrderDetail WHERE ProductID = 709 UNION SELECT * FROM Sales.SalesOrderDetail WHERE ProductID = 998 UNION SELECT * FROM Sales.SalesOrderDetail WHERE ProductID = 875 UNION SELECT * FROM Sales.SalesOrderDetail WHERE ProductID = 976 UNION SELECT * FROM Sales.SalesOrderDetail WHERE ProductID = 874 So query 1 is using OR and the later is using UNION. Let us analyze the execution plans for these queries. Query 1 Query 2 As expected Query 1 will use Clustered Index Scan but Query 2, uses all sorts of things. In this case, since it is using multiple CPUs you might have CX_PACKET waits as well. Let’s look at the profiler results for these two queries: CPU Reads Duration Row Counts OR 78 1252 389 3854 UNION 250 7495 660 3854 You can see from the above table the UNION query is not performing well as the  OR query though both are retuning same no of rows (3854).These results indicate that, for the above scenario UNION should be used. Scenario 2: Non-Clustered and Clustered Index Columns only --Query 1 : OR SELECT ProductID,SalesOrderID, SalesOrderDetailID FROM Sales.SalesOrderDetail WHERE ProductID = 714 OR ProductID =709 OR ProductID =998 OR ProductID =875 OR ProductID =976 OR ProductID =874 GO --Query 2 : UNION SELECT ProductID,SalesOrderID, SalesOrderDetailID FROM Sales.SalesOrderDetail WHERE ProductID = 714 UNION SELECT ProductID,SalesOrderID, SalesOrderDetailID FROM Sales.SalesOrderDetail WHERE ProductID = 709 UNION SELECT ProductID,SalesOrderID, SalesOrderDetailID FROM Sales.SalesOrderDetail WHERE ProductID = 998 UNION SELECT ProductID,SalesOrderID, SalesOrderDetailID FROM Sales.SalesOrderDetail WHERE ProductID = 875 UNION SELECT ProductID,SalesOrderID, SalesOrderDetailID FROM Sales.SalesOrderDetail WHERE ProductID = 976 UNION SELECT ProductID,SalesOrderID, SalesOrderDetailID FROM Sales.SalesOrderDetail WHERE ProductID = 874 GO So this time, we will be selecting only index columns, which means these queries will avoid a data page lookup. As in the previous case we will analyze the execution plans: Query 1 Query 2 Again, Query 2 is more complex than Query 1. Let us look at the profile analysis: CPU Reads Duration Row Counts OR 0 24 208 3854 UNION 0 38 193 3854 In this analyzis, there is only slight difference between OR and UNION. Scenario 3: Selecting all columns for different fields Up to now, we were using only one column (ProductID) in the where clause.  What if we have two columns for where clauses and let us assume both are covered by non-clustered indexes? --Query 1 : OR SELECT * FROM Sales.SalesOrderDetail WHERE ProductID = 714 OR CarrierTrackingNumber LIKE 'D0B8%' --Query 2 : UNION SELECT * FROM Sales.SalesOrderDetail WHERE ProductID = 714 UNION SELECT * FROM Sales.SalesOrderDetail WHERE CarrierTrackingNumber  LIKE 'D0B8%' Query 1 Query 2: As we can see, the query plan for the second query has improved. Let us see the profiler results. CPU Reads Duration Row Counts OR 47 1278 443 1228 UNION 31 1334 400 1228 So in this case too, there is little difference between OR and UNION. Scenario 4: Selecting Clustered index columns for different fields Now let us go only with clustered indexes: --Query 1 : OR SELECT * FROM Sales.SalesOrderDetail WHERE ProductID = 714 OR CarrierTrackingNumber LIKE 'D0B8%' --Query 2 : UNION SELECT * FROM Sales.SalesOrderDetail WHERE ProductID = 714 UNION SELECT * FROM Sales.SalesOrderDetail WHERE CarrierTrackingNumber  LIKE 'D0B8%' Query 1 Query 2 Now both execution plans are almost identical except is an additional Stream Aggregate is used in the first query. This means UNION has advantage over OR in this scenario. Let us see profiler results for these queries again. CPU Reads Duration Row Counts OR 0 319 366 1228 UNION 0 50 193 1228 Now see the differences, in this scenario UNION has somewhat of an advantage over OR. Conclusion Using UNION or OR depends on the scenario you are faced with. So you need to do your analyzing before selecting the appropriate method. Also, above the four scenarios are not all an exhaustive list of scenarios, I selected those for the broad description purposes only.

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• SQL SERVER – Puzzle to Win Print Book – Functions FIRST_VALUE and LAST_VALUE with OVER clause and ORDER BY

  - by pinaldave

  Some time an interesting feature and smart audience makes total difference at places. From last two days, I have been writing on SQL Server 2012 feature FIRST_VALUE and LAST_VALUE. Please read following post before I continue today as this question is based on the same. Introduction to FIRST_VALUE and LAST_VALUE Introduction to FIRST_VALUE and LAST_VALUE with OVER clause As a comment of the second post I received excellent question from Nilesh Molankar. He asks what will happen if we change few things in the T-SQL. I really like this question as this kind of questions will make us sharp and help us perform in critical situation in need. We recently publish SQL Server Interview Questions book. I promise that in future version of this book, we will for sure include this question. Instead of repeating his question, I am going to ask something very similar to his question. Let us first run following query (read yesterday’s blog post for more detail): USE AdventureWorks GO SELECT s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty, FIRST_VALUE(SalesOrderDetailID) OVER (PARTITION BY SalesOrderID ORDER BY SalesOrderDetailID ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) FstValue, LAST_VALUE(SalesOrderDetailID) OVER (PARTITION BY SalesOrderID ORDER BY SalesOrderDetailID ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) LstValue FROM Sales.SalesOrderDetail s WHERE SalesOrderID IN (43670, 43669, 43667, 43663) ORDER BY s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty GO Here is the resultset of the above query. Now let us change the ORDER BY clause of OVER clause in above query and see what is the new result. USE AdventureWorks GO SELECT s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty, FIRST_VALUE(SalesOrderDetailID) OVER (PARTITION BY SalesOrderID ORDER BY OrderQty ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) FstValue, LAST_VALUE(SalesOrderDetailID) OVER (PARTITION BY SalesOrderID ORDER BY OrderQty ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) LstValue FROM Sales.SalesOrderDetail s WHERE SalesOrderID IN (43670, 43669, 43667, 43663) ORDER BY s.SalesOrderID,s.SalesOrderDetailID,s.OrderQty GO Now let us see the result and ready for interesting question: Puzzle You can see that row number 2, 3, 4, and 5 has same SalesOrderID = 43667. The FIRST_VALUE is 78 and LAST_VALUE is 77. Now if these function was working on maximum and minimum value they should have given answer as 77 and 80 respectively instead of 78 and 77. Also the value of FIRST_VALUE is greater than LAST_VALUE 77. Why? Explain in detail. Hint Let me give you a simple hint. Just for simplicity I have changed the order of columns selected in the SELECT and ORDER BY (at the end). This will not change resultset but just order of the columns as well order of the rows. However, the data remains the same. USE AdventureWorks GO SELECT s.OrderQty,s.SalesOrderID,s.SalesOrderDetailID, FIRST_VALUE(SalesOrderDetailID) OVER (PARTITION BY SalesOrderID ORDER BY OrderQty ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) FstValue, LAST_VALUE(SalesOrderDetailID) OVER (PARTITION BY SalesOrderID ORDER BY OrderQty ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) LstValue FROM Sales.SalesOrderDetail s WHERE SalesOrderID IN (43670, 43669, 43667, 43663) ORDER BY s.OrderQty,s.SalesOrderID,s.SalesOrderDetailID GO Above query returns following result: Now I am very sure all of you have figured out the solution. Here is the second hint – pay attention to row 2, 3, 4, and 10. Hint2 T-SQL Enhancements: FIRST_VALUE() and LAST_VALUE() MSDN: FIRST_VALUE and LAST_VALUE Rules Leave a comment with your detailed answer by Nov 15′s blog post. Open world-wide (where Amazon ships books) If you blog about puzzle’s solution and if you win, you win additional surprise gift as well. Prizes Print copy of my new book SQL Server Interview Questions Amazon|Flipkart If you already have this book, you can opt for any of my other books SQL Wait Stats [Amazon|Flipkart|Kindle] and SQL Programming [Amazon|Flipkart|Kindle]. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Function, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• Sharepoint dynamic caml query problem?

  - by AB

  Hi, I want to dynamic caml query based on query string.Let me explain it with example my query sting can be anything ?cat=ABC&cat=ABD&cat=ABE... ?Cat=ABC ?Cat=ABC&cat=ABL so no. can be anything now the problem begins I want to query my sharepoint list based on this query string if (HttpContext.Current.Request.QueryString["cat"] != null) { string _cat = HttpContext.Current.Request.QueryString["cat"].ToString(); } so this way my string contains all the query string _cat=ABC,AD,....all. I want to query my sharepoint list based on these query string and with "AND" where title=ABC and title=AD .... if there is only one query string then only where title=ABC....so I want my query string should be dynamic.... Any idea how to acheive this??

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• could not resolve property (complex properties)

  - by felipeoriani

  I have a asp.net mvc application with NHibernate and I do not know how to resolve a problem to query some data. I have this query: // create query var query = session.QueryOVer<Laudo>().Fetch(x => x.Equipament).Eager; // add some filters if (idEquipament.HasValue) query = query.And(x => x.Equipament.Id == idEquipament.Value); //I got the error here... if (idCompany.HasValue) query = query.And(x => x.Equipament.Company.Id == idCompany.Value); When I try to execute this query, I've got an exception with this message: "could not resolve property: Equipament.Company.Id of: DomainModel.Laudo" what can I do to fix this problem? Thanks

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• SQL SEVER – Finding Memory Pressure – External and Internal

  - by pinaldave

  Following query will provide details of external and internal memory pressure. It will return the data how much portion in the existing memory is assigned to what kind of memory type. SELECT TYPE, SUM(single_pages_kb) InternalPressure, SUM(multi_pages_kb) ExtermalPressure FROM sys.dm_os_memory_clerks GROUP BY TYPE ORDER BY SUM(single_pages_kb) DESC, SUM(multi_pages_kb) DESC GO What is your method to find memory pressure? Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Optimization, SQL Performance, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• SQL SERVER – Challenge – Puzzle – Usage of FAST Hint

  - by pinaldave

  I was recently working with various SQL Server Hints. After working for a day on various hints, I realize that for one hint, I am not able to come up with good example. The hint is FAST. Let us look at the definition of the FAST hint from the Book On-Line. FAST number_rows Specifies that the query is optimized for fast retrieval of the first number_rows. This is a nonnegative integer. After the first number_rows are returned, the query continues execution and produces its full result set. Now the question is in what condition this hint can be useful. I have tried so many different combination, I have found this hint does not make much performance difference, infect I did not notice any change in time taken to load the resultset. I noticed that this hint does not change number of the page read to return result. Now when there is difference in performance is expected because if you read the what FAST hint does is that it only returns first few results FAST – which does not mean there will be difference in performance. I also understand that this hint gives the guidance/suggestions/hint to query optimizer that there are only 100 rows are in expected resultset. This tricking the optimizer to think there are only 100 rows and which (may) lead to render different execution plan than the one which it would have taken in normal case (without hint). Again, not necessarily, this will happen always. Now if you read above discussion, you will find that basic understanding of the hint is very clear to me but I still feel that I am missing something. Here are my questions: 1) In what condition this hint can be useful? What is the case, when someone want to see first few rows early because my experience suggests that when first few rows are rendered remaining rows are rendered as well. 2) Is there any way application can retrieve the fast fetched rows from SQL Server? 3) Do you use this hint in your application? Why? When? and How? Here are few examples I have attempted during the my experiment and found there is no difference in execution plan except its estimated number of rows are different leading optimizer think that the cost is less but in reality that is not the case. USE AdventureWorks GO SET STATISTICS IO ON SET STATISTICS TIME ON GO --------------------------------------------- -- Table Scan with Fast Hint SELECT * FROM Sales.SalesOrderDetail GO SELECT * FROM Sales.SalesOrderDetail OPTION (FAST 100) GO --------------------------------------------- -- Table Scan with Where on Index Key SELECT * FROM Sales.SalesOrderDetail WHERE OrderQty = 14 GO SELECT * FROM Sales.SalesOrderDetail WHERE OrderQty = 14 OPTION (FAST 100) GO --------------------------------------------- -- Table Scan with Where on Index Key SELECT * FROM Sales.SalesOrderDetail WHERE SalesOrderDetailID < 1000 GO SELECT * FROM Sales.SalesOrderDetail WHERE SalesOrderDetailID < 1000 OPTION (FAST 100) GO Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Pinal Dave, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• SQL SERVER – Tricks to Replace SELECT * with Column Names – SQL in Sixty Seconds #017 – Video

  - by pinaldave

  You might have heard many times that one should not use SELECT * as there are many disadvantages to the usage of the SELECT *. I also believe that there are always rare occasion when we need every single column of the query. In most of the cases, we only need a few columns of the query and we should retrieve only those columns. SELECT * has many disadvantages. Let me list a few and remaining you can add as a comment.  Retrieves unnecessary columns and increases network traffic When a new columns are added views needs to be refreshed manually Leads to usage of sub-optimal execution plan Uses clustered index in most of the cases instead of using optimal index It is difficult to debug. There are two quick tricks I have discussed in the video which explains how users can avoid using SELECT * but instead list the column names. 1) Drag the columns folder from SQL Server Management Studio to Query Editor 2) Right Click on Table Name >> Script TAble AS >> SELECT To… >> Select option It is extremely easy to list the column names in the table. In today’s sixty seconds video, you will notice that I was able to demonstrate both the methods very quickly. From now onwards there should be no excuse for not listing ColumnName. Let me ask a question back – is there ever a reason to SELECT *? If yes, would you please share that as a comment. More on SELECT *: SQL SERVER – Solution – Puzzle – SELECT * vs SELECT COUNT(*) SQL SERVER – Puzzle – SELECT * vs SELECT COUNT(*) SQL SERVER – SELECT vs. SET Performance Comparison I encourage you to submit your ideas for SQL in Sixty Seconds. We will try to accommodate as many as we can. If we like your idea we promise to share with you educational material. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Database, Pinal Dave, PostADay, SQL, SQL Authority, SQL in Sixty Seconds, SQL Query, SQL Scripts, SQL Server, SQL Server Management Studio, SQL Tips and Tricks, T SQL, Technology, Video

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• SQL SERVER – A Puzzle – Fun with NULL – Fix Error 8117

  - by pinaldave

  During my 8 years of career, I have been involved in many interviews. Quite often, I act as the  interview. If I am the interviewer, I ask many questions – from easy questions to difficult ones. When I am the interviewee, I frequently get an opportunity to ask the interviewer some questions back. Regardless of the my capacity in attending the interview, I always make it a point to ask the interviewer at least one question. What is NULL? It’s always fun to ask this question during interviews, because in every interview, I get a different answer. NULL is often confused with false, absence of value or infinite value. Honestly, NULL is a very interesting subject as it bases its behavior in server settings. There are a few properties of NULL that are universal, but the knowledge about these properties is not known in a universal sense. Let us run this simple puzzle. Run the following T-SQL script: SELECT SUM(data) FROM (SELECT NULL AS data) t It will return the following error: Msg 8117, Level 16, State 1, Line 1 Operand data type NULL is invalid for sum operator. Now the error makes it very clear that NULL is invalid for sum Operator. Frequently enough, I have showed this simple query to many folks whom I came across. I asked them if they could modify the subquery and return the result as NULL. Here is what I expected: Even though this is a very simple looking query, so far I’ve got the correct answer from only 10% of the people to whom I have asked this question. It was common for me to receive this kind of answer – convert the NULL to some data type. However, doing so usually returns the value as 0 or the integer they passed. SELECT SUM(data) FROM (SELECT ISNULL(NULL,0) AS data) t I usually see many people modifying the outer query to get desired NULL result, but that is not allowed in this simple puzzle. This small puzzle made me wonder how many people have a clear understanding about NULL. Well, here is the answer to my simple puzzle. Just CAST NULL AS INT and it will return the final result as NULL: SELECT SUM(data) FROM (SELECT CAST(NULL AS INT) AS data) t Now that you know the answer, don’t you think it was very simple indeed? This blog post is especially dedicated to my friend Madhivanan who has written an excellent blog post about NULL. I am confident that after reading the blog post from Madhivanan, you will have no confusion regarding NULL in the future. Read: NULL, NULL, NULL and nothing but NULL. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Puzzle, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• SQL SERVER – Find Referenced or Referencing Object in SQL Server using sys.sql_expression_dependencies

  - by pinaldave

  A very common question which I often receive are: How do I find all the tables used in a particular stored procedure? How do I know which stored procedures are using a particular table? Both are valid question but before we see the answer of this question – let us understand two small concepts – Referenced and Referencing. Here is the sample stored procedure. CREATE PROCEDURE mySP AS SELECT * FROM Sales.Customer GO Reference: The table Sales.Customer is the reference object as it is being referenced in the stored procedure mySP. Referencing: The stored procedure mySP is the referencing object as it is referencing Sales.Customer table. Now we know what is referencing and referenced object. Let us run following queries. I am using AdventureWorks2012 as a sample database. If you do not have SQL Server 2012 here is the way to get SQL Server 2012 AdventureWorks database. Find Referecing Objects of a particular object Here we are finding all the objects which are using table Customer in their object definitions (regardless of the schema). USE AdventureWorks GO SELECT referencing_schema_name = SCHEMA_NAME(o.SCHEMA_ID), referencing_object_name = o.name, referencing_object_type_desc = o.type_desc, referenced_schema_name, referenced_object_name = referenced_entity_name, referenced_object_type_desc = o1.type_desc, referenced_server_name, referenced_database_name --,sed.* -- Uncomment for all the columns FROM sys.sql_expression_dependencies sed INNER JOIN sys.objects o ON sed.referencing_id = o.[object_id] LEFT OUTER JOIN sys.objects o1 ON sed.referenced_id = o1.[object_id] WHERE referenced_entity_name = 'Customer' The above query will return all the objects which are referencing the table Customer. Find Referenced Objects of a particular object Here we are finding all the objects which are used in the view table vIndividualCustomer. USE AdventureWorks GO SELECT referencing_schema_name = SCHEMA_NAME(o.SCHEMA_ID), referencing_object_name = o.name, referencing_object_type_desc = o.type_desc, referenced_schema_name, referenced_object_name = referenced_entity_name, referenced_object_type_desc = o1.type_desc, referenced_server_name, referenced_database_name --,sed.* -- Uncomment for all the columns FROM sys.sql_expression_dependencies sed INNER JOIN sys.objects o ON sed.referencing_id = o.[object_id] LEFT OUTER JOIN sys.objects o1 ON sed.referenced_id = o1.[object_id] WHERE o.name = 'vIndividualCustomer' The above query will return all the objects which are referencing the table Customer. I am just glad to write above query. There are more to write to this subject. In future blog post I will write more in depth about other DMV which also aids in finding referenced data. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: PostADay, SQL, SQL Authority, SQL DMV, SQL Query, SQL Server, SQL Tips and Tricks, SQL Utility, T SQL, Technology

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• SQL SERVER – Weekly Series – Memory Lane – #048

  - by Pinal Dave

  Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 Order of Result Set of SELECT Statement on Clustered Indexed Table When ORDER BY is Not Used Above theory is true in most of the cases. However SQL Server does not use that logic when returning the resultset. SQL Server always returns the resultset which it can return fastest.In most of the cases the resultset which can be returned fastest is the resultset which is returned using clustered index. Effect of TRANSACTION on Local Variable – After ROLLBACK and After COMMIT One of the Jr. Developer asked me this question (What will be the Effect of TRANSACTION on Local Variable – After ROLLBACK and After COMMIT?) while I was rushing to an important meeting. I was getting late so I asked him to talk with his Application Tech Lead. When I came back from meeting both of them were looking for me. They said they are confused. I quickly wrote down following example for them. 2008 SQL SERVER – Guidelines and Coding Standards Complete List Download Coding standards and guidelines are very important for any developer on the path of a successful career. A coding standard is a set of guidelines, rules and regulations on how to write code. Coding standards should be flexible enough or should take care of the situation where they should not prevent best practices for coding. They are basically the guidelines that one should follow for better understanding. Download Guidelines and Coding Standards complete List Download Get Answer in Float When Dividing of Two Integer Many times we have requirements of some calculations amongst different fields in Tables. One of the software developers here was trying to calculate some fields having integer values and divide it which gave incorrect results in integer where accurate results including decimals was expected. Puzzle – Computed Columns Datatype Explanation SQL Server automatically does a cast to the data type having the highest precedence. So the result of INT and INT will be INT, but INT and FLOAT will be FLOAT because FLOAT has a higher precedence. If you want a different data type, you need to do an EXPLICIT cast. Renaming SP is Not Good Idea – Renaming Stored Procedure Does Not Update sys.procedures I have written many articles about renaming a tables, columns and procedures SQL SERVER – How to Rename a Column Name or Table Name, here I found something interesting about renaming the stored procedures and felt like sharing it with you all. The interesting fact is that when we rename a stored procedure using SP_Rename command, the Stored Procedure is successfully renamed. But when we try to test the procedure using sp_helptext, the procedure will be having the old name instead of new names. 2009 Insert Values of Stored Procedure in Table – Use Table Valued Function It is clear from the result set that , where I have converted stored procedure logic into the table valued function, is much better in terms of logic as it saves a large number of operations. However, this option should be used carefully. The performance of the stored procedure is “usually” better than that of functions. Interesting Observation – Index on Index View Used in Similar Query Recently, I was working on an optimization project for one of the largest organizations. While working on one of the queries, we came across a very interesting observation. We found that there was a query on the base table and when the query was run, it used the index, which did not exist in the base table. On careful examination, we found that the query was using the index that was on another view. This was very interesting as I have personally never experienced a scenario like this. In simple words, “Query on the base table can use the index created on the indexed view of the same base table.” Interesting Observation – Execution Plan and Results of Aggregate Concatenation Queries Working with SQL Server has never seemed to be monotonous – no matter how long one has worked with it. Quite often, I come across some excellent comments that I feel like acknowledging them as blog posts. Recently, I wrote an article on SQL SERVER – Execution Plan and Results of Aggregate Concatenation Queries Depend Upon Expression Location, which is well received in the community. 2010 I encourage all of you to go through complete series and write your own on the subject. If you write an article and send it to me, I will publish it on this blog with due credit to you. If you write on your own blog, I will update this blog post pointing to your blog post. SQL SERVER – ORDER BY Does Not Work – Limitation of the View 1 SQL SERVER – Adding Column is Expensive by Joining Table Outside View – Limitation of the View 2 SQL SERVER – Index Created on View not Used Often – Limitation of the View 3 SQL SERVER – SELECT * and Adding Column Issue in View – Limitation of the View 4 SQL SERVER – COUNT(*) Not Allowed but COUNT_BIG(*) Allowed – Limitation of the View 5 SQL SERVER – UNION Not Allowed but OR Allowed in Index View – Limitation of the View 6 SQL SERVER – Cross Database Queries Not Allowed in Indexed View – Limitation of the View 7 SQL SERVER – Outer Join Not Allowed in Indexed Views – Limitation of the View 8 SQL SERVER – SELF JOIN Not Allowed in Indexed View – Limitation of the View 9 SQL SERVER – Keywords View Definition Must Not Contain for Indexed View – Limitation of the View 10 SQL SERVER – View Over the View Not Possible with Index View – Limitations of the View 11 2011 Startup Parameters Easy to Configure If you are a regular reader of this blog, you must be aware that I have written about SQL Server Denali recently. Here is the quickest way to reach into the screen where we can change the startup parameters. Go to SQL Server Configuration Manager >> SQL Server Services >> Right Click on the Server >> Properties >> Startup Parameters 2012 Validating Unique Columnname Across Whole Database I sometimes come across very strange requirements and often I do not receive a proper explanation of the same. Here is the one of those examples. For example “Our business requirement is when we add new column we want it unique across current database.” Read the solution to this strange request in this blog post. Excel Losing Decimal Values When Value Pasted from SSMS ResultSet It is very common when users are coping the resultset to Excel, the floating point or decimals are missed. The solution is very much simple and it requires a small adjustment in the Excel. By default Excel is very smart and when it detects the value which is getting pasted is numeric it changes the column format to accommodate that. Basic Calculation and PEMDAS Order of Operation Read this interesting blog post for fantastic conversation about the subject. Copy Column Headers from Resultset – SQL in Sixty Seconds #027 – Video http://www.youtube.com/watch?v=x_-3tLqTRv0 Delete From Multiple Table – Update Multiple Table in Single Statement There are two questions which I get every single day multiple times. In my gmail, I have created standard canned reply for them. Let us see the questions here. I want to delete from multiple table in a single statement how will I do it? I want to update multiple table in a single statement how will I do it? Read the answer in the blog post. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• SQL University: Parallelism Week - Part 3, Settings and Options

  - by Adam Machanic

  Congratulations! You've made it back for the the third and final installment of Parallelism Week here at SQL University . So far we've covered the fundamentals of multitasking vs. parallel processing and delved into how parallel query plans actually work . Today we'll take a look at the settings and options that influence intra-query parallelism and discuss how best to set things up in various situations. Instance-Level Configuration Your database server probably has more than one logical processor....(read more)

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• SQL SERVER – BI Quiz Hint – Performance Tuning Cubes – Hints

  - by pinaldave

  I earlier wrote about SQL BI Quiz over here and here. The details of the quiz is here: Working with huge data is very common when it is about Data Warehousing. It is necessary to create Cubes on the data to make it meaningful and consumable. There are cases when retrieving the data from cube takes lots of the time. Let us assume that your cube is returning you data very quickly. Suddenly on one day it is returning the data very slowly. What are the three things will you to diagnose this. After diagnose what you will do to resolve performance issue. Participate in my question over here I required BI Expert Jason Thomas to help with few hints to blog readers. He is one of the leading SSAS expert and writes a complicated subject in simple words. If queries were executing properly before but now take a long time to return the data, it means that there has been a change in the environment in which it is running. Some possible changes are listed below:-  1) Data factors:- Compare the data size then and now. Increase in data can result in different execution times. Poorly written queries as well as poor design will not start showing issues till the data grows. How to find it out? (Ans : SQL Server profiler and Perfmon Counters can be used for identifying the issues and performance  tuning the MDX queries)  2) Internal Factors:- Is some slow MDX query / multiple mdx queries running at the same time, which was not running when you had tested it before? Is there any locking happening due to proactive caching or processing operations? Are the measure group caches being cleared by processing operations? (Ans : Again, profiler and perfmon counters will help in finding it out. Load testing can be done using AS Performance Workbench (http://asperfwb.codeplex.com/) by running multiple queries at once)  3) External factors:- Is some other application competing for the same resources?  HINT : Read “Identifying and Resolving MDX Query Performance Bottlenecks in SQL Server 2005 Analysis Services” (http://sqlcat.com/whitepapers/archive/2007/12/16/identifying-and-resolving-mdx-query-performance-bottlenecks-in-sql-server-2005-analysis-services.aspx) Well, these are great tips. Now win big prizes by participate in my question over here. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• SQLbits London 2012 - Demos

  - by Adam Machanic

  Thanks to everyone who attended my sessions last Friday and Saturday at SQLbits! It was great to meet many new people, not to mention spending some time exploring one of my favorite cities, London. Attached are the demos for each of the two talks I delivered: Query Tuning Mastery: The Art of and Science of Manhandling Parallelism As a database developer, your job boils down to one word: performance. And in today's multi-core-driven world, query performance is very much determined by how well you're...(read more)

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• Is there an equivalent of jsqlparser but for SPARQL instead of SQL?

  - by Programmer

  I'm trying to use Java to construct a SPARQL query, and then send it off to a remote database. However, I'm new to both Java and SPARQL, so I was wondering if anyone could explain how to do this, rather than just posting a link. I heard there is a tool called jsqlparser for the same task, except that it's for a SQL to SPARQL conversion using Java. Conversion nor parser won't be necessary, just a method for constructing a query and querying the database provided by the user.

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• Why isn't my query using any indices when I use a subquery?

  - by sfussenegger

  I have the following tables (removed columns that aren't used for my examples): CREATE TABLE `person` ( `id` int(11) NOT NULL, `name` varchar(1024) NOT NULL, `sortname` varchar(1024) NOT NULL, PRIMARY KEY (`id`), KEY `sortname` (`sortname`(255)), KEY `name` (`name`(255)) ); CREATE TABLE `personalias` ( `id` int(11) NOT NULL, `person` int(11) NOT NULL, `name` varchar(1024) NOT NULL, PRIMARY KEY (`id`), KEY `person` (`person`), KEY `name` (`name`(255)) ) Currently, I'm using this query which works just fine: select p.* from person p where name = 'John Mayer' or sortname = 'John Mayer'; mysql> explain select p.* from person p where name = 'John Mayer' or sortname = 'John Mayer'; +----+-------------+-------+-------------+---------------+---------------+---------+------+------+----------------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+-------------+---------------+---------------+---------+------+------+----------------------------------------------+ | 1 | SIMPLE | p | index_merge | name,sortname | name,sortname | 767,767 | NULL | 3 | Using sort_union(name,sortname); Using where | +----+-------------+-------+-------------+---------------+---------------+---------+------+------+----------------------------------------------+ 1 row in set (0.00 sec) Now I'd like to extend this query to also consider aliases. First, I've tried using a join: select p.* from person p join personalias a where p.name = 'John Mayer' or p.sortname = 'John Mayer' or a.name = 'John Mayer'; mysql> explain select p.* from person p join personalias a on p.id = a.person where p.name = 'John Mayer' or p.sortname = 'John Mayer' or a.name = 'John Mayer'; +----+-------------+-------+--------+-----------------------+---------+---------+-------------------+-------+-----------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+--------+-----------------------+---------+---------+-------------------+-------+-----------------+ | 1 | SIMPLE | a | ALL | ref,name | NULL | NULL | NULL | 87401 | Using temporary | | 1 | SIMPLE | p | eq_ref | PRIMARY,name,sortname | PRIMARY | 4 | musicbrainz.a.ref | 1 | Using where | +----+-------------+-------+--------+-----------------------+---------+---------+-------------------+-------+-----------------+ 2 rows in set (0.00 sec) This looks bad: no index, 87401 rows, using temporary. Using temporary only appears when I use distinct, but as an alias might be the same as the name, I can't really get rid of it. Next, I've tried to replace the join with a subquery: select p.* from person p where p.name = 'John Mayer' or p.sortname = 'John Mayer' or p.id in (select person from personalias a where a.name = 'John Mayer'); mysql> explain select p.* from person p where p.name = 'John Mayer' or p.sortname = 'John Mayer' or p.id in (select id from personalias a where a.name = 'John Mayer'); +----+--------------------+-------+----------------+------------------+--------+---------+------+--------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+--------------------+-------+----------------+------------------+--------+---------+------+--------+-------------+ | 1 | PRIMARY | p | ALL | name,sortname | NULL | NULL | NULL | 540309 | Using where | | 2 | DEPENDENT SUBQUERY | a | index_subquery | person,name | person | 4 | func | 1 | Using where | +----+--------------------+-------+----------------+------------------+--------+---------+------+--------+-------------+ 2 rows in set (0.00 sec) Again, this looks pretty bad: no index, 540309 rows. Interestingly, both queries (select p.* from person ... or p.id in (4711,12345) and select id from personalias a where a.name = 'John Mayer') work extremely well. Why doesn't MySQL use any indices for both of my queries? What else could I do? Currently, it looks best to fetch person.ids for aliases and add them statically as an in(...) to the second query. There certainly has to be another way to do this with a single query. I'm currently out of ideas though. Could I somehow force MySQL into using another (better) query plan?

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• How to add Spatial Solr to a Solrnet query

  - by Flo

  Hi, I am running Solr on my windows machine using jetty. I have downloaded the Spatial Solr Plugin which I finally managed to get up and running. I am also using Solrnet to query against Solr from my asp.net mvc project. Now, adding data into my index seems to work fine and the SpatialTierUpdateProcessorFactory does work as well. The problem is: How do I add the spatial query to my normal query using the Solrnet library. I have tried adding it using the "ExtraParams" parameter but that didn't work very well. Here is an example of me trying to combine the spatial query with a data range query. The date range query works fine without the spatial query attached to it: new SolrQuery("{!spatial lat=51.5224 long=-2.6257 radius=10000 unit=km calc=arc threadCount=2}") && new SolrQuery(MyCustomQuery.Query) && new SolrQuery(DateRangeQuery); which results in the following query against Solr: (({!spatial lat=51.5224 long=-2.6257 radius=100 unit=km calc=arc threadCount=2} AND *:*) AND _date:[2010-05-07T13:13:37Z TO 2011-05-07T13:13:37Z]) And the error message I get back is: The remote server returned an error: (400) Bad Request. SEVERE: org.apache.solr.common.SolrException: org.apache.lucene.queryParser.Pars eException: Cannot parse '(({!spatial lat=51.5224 lng=-2.6257 radius=10000 unit= km calc=arc threadCount=2} AND *:*) AND _date:[2010-05-07T13:09:49Z TO 2011-05-0 7T13:09:49Z])': Encountered " <RANGEEX_GOOP> "lng=-2.6257 "" at line 1, column 2 4. Was expecting: "}" ... Now, the thing is if I use the Solr Web Admin page and execute the following query against it, everything works fine. {!spatial lat=50.8371 long=4.35536 radius=100 calc=arc unit=km threadcount=2}text:London What is the best/correct way to call the spatial function using SolrNet. Is the best way to somehow add that bit of the query manually to the query string and is so how? Any help is much appreciated!

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• Tiff Analyzer

  - by Kevin

  I am writing a program to convert some data, mainly a bunch of Tiff images. Some of the Tiffs seems to have a minor problem with them. They show up fine in some viewers (Irfanview, client's old system) but not in others (Client's new system, Window's picture and fax viewer). I have manually looked at the binary data and all the tags seem ok. Can anyone recommend an app that can analyze it and tell me what, if anything, is wrong with it? Also, for clarity sake, I'm only converting the data about the images which is stored seperately in a database and copying the images, I'm not editting the images myself, so I'm pretty sure I'm not messing them up. UDPATE: For anyone interested, here are the tags from a good and bad file: BAD Tag Type Length Value 256 Image Width SHORT 1 1652 257 Image Length SHORT 1 704 258 Bits Per Sample SHORT 1 1 259 Compression SHORT 1 4 262 Photometric SHORT 1 0 266 Fill Order SHORT 1 1 273 Strip Offsets LONG 1 210 (d2 Hex) 274 Orientation SHORT 1 3 277 Samples Per Pixel SHORT 1 1 278 Rows Per Strip SHORT 1 450 279 Strip Byte Counts LONG 1 7264 (1c60 Hex) 282 X Resolution RATIONAL 1 <194 200 / 1 = 200.000 283 Y Resolution RATIONAL 1 <202 200 / 1 = 200.000 284 Planar Configuration SHORT 1 1 296 Resolution Unit SHORT 1 2 Good Tag Type Length Value 254 New Subfile Type LONG 1 0 (0 Hex) 256 Image Width SHORT 1 1193 257 Image Length SHORT 1 788 258 Bits Per Sample SHORT 1 1 259 Compression SHORT 1 4 262 Photometric SHORT 1 0 266 Fill Order SHORT 1 1 270 Image Description ASCII 45 256 273 Strip Offsets LONG 1 1118 (45e Hex) 274 Orientation SHORT 1 1 277 Samples Per Pixel SHORT 1 1 278 Rows Per Strip LONG 1 788 (314 Hex) 279 Strip Byte Counts LONG 1 496 (1f0 Hex) 280 Min Sample Value SHORT 1 0 281 Max Sample Value SHORT 1 1 282 X Resolution RATIONAL 1 <301 200 / 1 = 200.000 283 Y Resolution RATIONAL 1 <309 200 / 1 = 200.000 284 Planar Configuration SHORT 1 1 293 Group 4 Options LONG 1 0 (0 Hex) 296 Resolution Unit SHORT 1 2

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• Big problem with regular expression in Lex (lexical analyzer)

  - by Nazgulled

  Hi, I have some content like this: author = "Marjan Mernik and Viljem Zumer", title = "Implementation of multiple attribute grammar inheritance in the tool LISA", year = 1999 author = "Manfred Broy and Martin Wirsing", title = "Generalized Heterogeneous Algebras and Partial Interpretations", year = 1983 author = "Ikuo Nakata and Masataka Sassa", title = "L-Attributed LL(1)-Grammars are LR-Attributed", journal = "Information Processing Letters" And I need to catch everything between double quotes for title. My first try was this: ^(" "|\t)+"title"" "*=" "*"\"".+"\"," Which catches the first example, but not the other two. The other have multiple lines and that's the problem. I though about changing to something with \n somewhere to allow multiple lines, like this: ^(" "|\t)+"title"" "*=" "*"\""(.|\n)+"\"," But this doesn't help, instead, it catches everything. Than I though, "what I want is between double quotes, what if I catch everything until I find another " followed by ,? This way I could know if I was at the end of the title or not, no matter the number of lines, like this: ^(" "|\t)+"title"" "*=" "*"\""[^"\""]+"," But this has another problem... The example above doesn't have it, but the double quote symbol (") can be in between the title declaration. For instance: title = "aaaaaaa \"X bbbbbb", And yes, it will always be preceded by a backslash (\). Any suggestions to fix this regexp?

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• Localhost packet analyzer for Mac

  - by kingjeffrey

  Packet sniffers generally do not capture localhost traffic. I need to inspect some post data in a localhost environment (being generated from a Ruby on Rails development). Do you know of any programs that expose localhost packets?

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• Error compiling flex (the lexical analyzer)

  - by Maulrus

  I'm trying to install flex on my Windows computer. I have MSYS installed. I untar flex, ./configure it, but when I try to make it, I get this error: In file included from ccl.c:34: flexdef.h:94:19: error: regex.h: No such file or directory In file included from ccl.c:34: flexdef.h:1195: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'regex_linedir' flexdef.h:1197: error: expected ')' before '*' token flexdef.h:1198: error: expected ')' before '*' token flexdef.h:1199: error: expected ')' before '*' token flexdef.h:1200: error: expected ')' before '*' token flexdef.h:1201: error: expected ')' before '*' token flexdef.h:1202: error: expected ')' before '*' token make[2]: *** [ccl.o] Error 1 make[1]: *** [all-recursive] Error 1 make: *** [all] Error 2 Until recently, I've only ever installed things using an .exe, so I'm pretty confused by this. Installing bison and m4 both went smoothly, and I'm wondering why this isn't. Any ideas?

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• Bison input analyzer - basic question on optional grammer and input interpretation

  - by kumar_m_kiran

  Hi All, I am very new to Flex/Bison, So it is very navie question. Pardon me if so. May look like homework question - but I need to implement project based on below concept. My question is related to two parts, Question 1 In Bison parser, How do I provide rules for optional input. Like, I need to parse the statment Example : -country='USA' -state='INDIANA' -population='100' -ratio='0.5' -comment='Census study for Indiana' Here the ratio token can be optional. Similarly, If I have many tokens optional, then How do I provide the grammer in the parser for the same? My code looks like, %start program program : TK_COUNTRY TK_IDENTIFIER TK_STATE TK_IDENTIFIER TK_POPULATION TK_IDENTIFIER ... where all the tokens are defined in the lexer. Since there are many tokens which are optional, If I use "|" then there will be many different ways of input combination possible. Question 2 There are good chance that the comment might have quotes as part of the input, so I have added a token -tag which user can provide to interpret the same, Example : -country='USA' -state='INDIANA' -population='100' -ratio='0.5' -comment='Census study for Indiana$'s population' -tag=$ Now, I need to reinterpret Indiana$'s as Indiana's since -tag=$. Please provide any input or related material for to understand these topic. Thanks for your input in advance.

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• Per Application Packet Analyzer

  - by Anindya Chatterjee

  Is there any tool which can analyze network traffic per application? Wireshark does not have per application filtering, fiddler also does not give proper logging for any application. So can anyone please help me out to find an app which can analyze network traffic originating from a random application and log the traffic for that particular application only?

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• MySQL Query That Can Pull the Data I am Seeking?

  - by Amy

  On the project I am working on, I am stuck with the table structure from Hades. Two things to keep in mind: I can't change the table structure right now. I'm stuck with it for the time being. The queries are dynamically generated and not hard coded. So, while I am asking for a query that can pull this data, what I am really working toward is an algorithm that will generate the query I need. Hopefully, I can explain the problem without making your eyes glaze over and your brain implode. We have an instance table that looks (simplified) along these lines: Instances InstanceID active 1 Y 2 Y 3 Y 4 N 5 Y 6 Y Then, there are multiple data tables along these lines: Table1 InstanceID field1 reference_field2 1 John 5 2 Sally NULL 3 Fred 6 4 Joe NULL Table2 InstanceID field3 5 1 6 1 Table3 InstanceID fieldID field4 5 1 Howard 5 2 James 6 2 Betty Please note that reference_field2 in Table1 contains a reference to another instance. Field3 in Table2 is a bit more complicated. It contains a fieldID for Table 3. What I need is a query that will get me a list as follows: InstanceID field1 field4 1 John Howard 2 Sally 3 Fred The problem is, in the query I currently have, I do not get Fred because there is no entry in Table3 for fieldID 1 and InstanceID 6. So, the very best list I have been able to get thus far is InstanceID field1 field4 1 John Howard 2 Sally In essence, if there is an entry in Table1 for Field 2, and there is not an entry in Table 3 that has the instanceID contained in field2 and the field ID contained in field3, I don't get the data from field1. I have looked at joins till I'm blue in the face, and I can't see a way to handle the case when table3 has no entry.

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