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  • SQL SERVER – 2008 – Missing Index Script – Download

    - by pinaldave
    Download Missing Index Script with Unused Index Script Performance Tuning is quite interesting and Index plays a vital role in it. A proper index can improve the performance and a bad index can hamper the performance. Here is the script from my script bank which I use to identify missing indexes on any database. Please note, if you should not create all the missing indexes this script suggest. This is just for guidance. You should not create more than 5-10 indexes per table. Additionally, this script sometime does not give accurate information so use your common sense. Any way, the scripts is good starting point. You should pay attention to Avg_Estimated_Impact when you are going to create index. The index creation script is also provided in the last column. Download Missing Index Script with Unused Index Script -- Missing Index Script -- Original Author: Pinal Dave (C) 2011 SELECT TOP 25 dm_mid.database_id AS DatabaseID, dm_migs.avg_user_impact*(dm_migs.user_seeks+dm_migs.user_scans) Avg_Estimated_Impact, dm_migs.last_user_seek AS Last_User_Seek, OBJECT_NAME(dm_mid.OBJECT_ID,dm_mid.database_id) AS [TableName], 'CREATE INDEX [IX_' + OBJECT_NAME(dm_mid.OBJECT_ID,dm_mid.database_id) + '_' + REPLACE(REPLACE(REPLACE(ISNULL(dm_mid.equality_columns,''),', ','_'),'[',''),']','') + CASE WHEN dm_mid.equality_columns IS NOT NULL AND dm_mid.inequality_columns IS NOT NULL THEN '_' ELSE '' END + REPLACE(REPLACE(REPLACE(ISNULL(dm_mid.inequality_columns,''),', ','_'),'[',''),']','') + ']' + ' ON ' + dm_mid.statement + ' (' + ISNULL (dm_mid.equality_columns,'') + CASE WHEN dm_mid.equality_columns IS NOT NULL AND dm_mid.inequality_columns IS NOT NULL THEN ',' ELSE '' END + ISNULL (dm_mid.inequality_columns, '') + ')' + ISNULL (' INCLUDE (' + dm_mid.included_columns + ')', '') AS Create_Statement FROM sys.dm_db_missing_index_groups dm_mig INNER JOIN sys.dm_db_missing_index_group_stats dm_migs ON dm_migs.group_handle = dm_mig.index_group_handle INNER JOIN sys.dm_db_missing_index_details dm_mid ON dm_mig.index_handle = dm_mid.index_handle WHERE dm_mid.database_ID = DB_ID() ORDER BY Avg_Estimated_Impact DESC GO Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Download, SQL Index, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • SQL Spatial: Getting “nearest” calculations working properly

    - by Rob Farley
    If you’ve ever done spatial work with SQL Server, I hope you’ve come across the ‘nearest’ problem. You have five thousand stores around the world, and you want to identify the one that’s closest to a particular place. Maybe you want the store closest to the LobsterPot office in Adelaide, at -34.925806, 138.605073. Or our new US office, at 42.524929, -87.858244. Or maybe both! You know how to do this. You don’t want to use an aggregate MIN or MAX, because you want the whole row, telling you which store it is. You want to use TOP, and if you want to find the closest store for multiple locations, you use APPLY. Let’s do this (but I’m going to use addresses in AdventureWorks2012, as I don’t have a list of stores). Oh, and before I do, let’s make sure we have a spatial index in place. I’m going to use the default options. CREATE SPATIAL INDEX spin_Address ON Person.Address(SpatialLocation); And my actual query: WITH MyLocations AS (SELECT * FROM (VALUES ('LobsterPot Adelaide', geography::Point(-34.925806, 138.605073, 4326)),                        ('LobsterPot USA', geography::Point(42.524929, -87.858244, 4326))                ) t (Name, Geo)) SELECT l.Name, a.AddressLine1, a.City, s.Name AS [State], c.Name AS Country FROM MyLocations AS l CROSS APPLY (     SELECT TOP (1) *     FROM Person.Address AS ad     ORDER BY l.Geo.STDistance(ad.SpatialLocation)     ) AS a JOIN Person.StateProvince AS s     ON s.StateProvinceID = a.StateProvinceID JOIN Person.CountryRegion AS c     ON c.CountryRegionCode = s.CountryRegionCode ; Great! This is definitely working. I know both those City locations, even if the AddressLine1s don’t quite ring a bell. I’m sure I’ll be able to find them next time I’m in the area. But of course what I’m concerned about from a querying perspective is what’s happened behind the scenes – the execution plan. This isn’t pretty. It’s not using my index. It’s sucking every row out of the Address table TWICE (which sucks), and then it’s sorting them by the distance to find the smallest one. It’s not pretty, and it takes a while. Mind you, I do like the fact that it saw an indexed view it could use for the State and Country details – that’s pretty neat. But yeah – users of my nifty website aren’t going to like how long that query takes. The frustrating thing is that I know that I can use the index to find locations that are within a particular distance of my locations quite easily, and Microsoft recommends this for solving the ‘nearest’ problem, as described at http://msdn.microsoft.com/en-au/library/ff929109.aspx. Now, in the first example on this page, it says that the query there will use the spatial index. But when I run it on my machine, it does nothing of the sort. I’m not particularly impressed. But what we see here is that parallelism has kicked in. In my scenario, it’s split the data up into 4 threads, but it’s still slow, and not using my index. It’s disappointing. But I can persuade it with hints! If I tell it to FORCESEEK, or use my index, or even turn off the parallelism with MAXDOP 1, then I get the index being used, and it’s a thing of beauty! Part of the plan is here: It’s massive, and it’s ugly, and it uses a TVF… but it’s quick. The way it works is to hook into the GeodeticTessellation function, which is essentially finds where the point is, and works out through the spatial index cells that surround it. This then provides a framework to be able to see into the spatial index for the items we want. You can read more about it at http://msdn.microsoft.com/en-us/library/bb895265.aspx#tessellation – including a bunch of pretty diagrams. One of those times when we have a much more complex-looking plan, but just because of the good that’s going on. This tessellation stuff was introduced in SQL Server 2012. But my query isn’t using it. When I try to use the FORCESEEK hint on the Person.Address table, I get the friendly error: Msg 8622, Level 16, State 1, Line 1 Query processor could not produce a query plan because of the hints defined in this query. Resubmit the query without specifying any hints and without using SET FORCEPLAN. And I’m almost tempted to just give up and move back to the old method of checking increasingly large circles around my location. After all, I can even leverage multiple OUTER APPLY clauses just like I did in my recent Lookup post. WITH MyLocations AS (SELECT * FROM (VALUES ('LobsterPot Adelaide', geography::Point(-34.925806, 138.605073, 4326)),                        ('LobsterPot USA', geography::Point(42.524929, -87.858244, 4326))                ) t (Name, Geo)) SELECT     l.Name,     COALESCE(a1.AddressLine1,a2.AddressLine1,a3.AddressLine1),     COALESCE(a1.City,a2.City,a3.City),     s.Name AS [State],     c.Name AS Country FROM MyLocations AS l OUTER APPLY (     SELECT TOP (1) *     FROM Person.Address AS ad     WHERE l.Geo.STDistance(ad.SpatialLocation) < 1000     ORDER BY l.Geo.STDistance(ad.SpatialLocation)     ) AS a1 OUTER APPLY (     SELECT TOP (1) *     FROM Person.Address AS ad     WHERE l.Geo.STDistance(ad.SpatialLocation) < 5000     AND a1.AddressID IS NULL     ORDER BY l.Geo.STDistance(ad.SpatialLocation)     ) AS a2 OUTER APPLY (     SELECT TOP (1) *     FROM Person.Address AS ad     WHERE l.Geo.STDistance(ad.SpatialLocation) < 20000     AND a2.AddressID IS NULL     ORDER BY l.Geo.STDistance(ad.SpatialLocation)     ) AS a3 JOIN Person.StateProvince AS s     ON s.StateProvinceID = COALESCE(a1.StateProvinceID,a2.StateProvinceID,a3.StateProvinceID) JOIN Person.CountryRegion AS c     ON c.CountryRegionCode = s.CountryRegionCode ; But this isn’t friendly-looking at all, and I’d use the method recommended by Isaac Kunen, who uses a table of numbers for the expanding circles. It feels old-school though, when I’m dealing with SQL 2012 (and later) versions. So why isn’t my query doing what it’s supposed to? Remember the query... WITH MyLocations AS (SELECT * FROM (VALUES ('LobsterPot Adelaide', geography::Point(-34.925806, 138.605073, 4326)),                        ('LobsterPot USA', geography::Point(42.524929, -87.858244, 4326))                ) t (Name, Geo)) SELECT l.Name, a.AddressLine1, a.City, s.Name AS [State], c.Name AS Country FROM MyLocations AS l CROSS APPLY (     SELECT TOP (1) *     FROM Person.Address AS ad     ORDER BY l.Geo.STDistance(ad.SpatialLocation)     ) AS a JOIN Person.StateProvince AS s     ON s.StateProvinceID = a.StateProvinceID JOIN Person.CountryRegion AS c     ON c.CountryRegionCode = s.CountryRegionCode ; Well, I just wasn’t reading http://msdn.microsoft.com/en-us/library/ff929109.aspx properly. The following requirements must be met for a Nearest Neighbor query to use a spatial index: A spatial index must be present on one of the spatial columns and the STDistance() method must use that column in the WHERE and ORDER BY clauses. The TOP clause cannot contain a PERCENT statement. The WHERE clause must contain a STDistance() method. If there are multiple predicates in the WHERE clause then the predicate containing STDistance() method must be connected by an AND conjunction to the other predicates. The STDistance() method cannot be in an optional part of the WHERE clause. The first expression in the ORDER BY clause must use the STDistance() method. Sort order for the first STDistance() expression in the ORDER BY clause must be ASC. All the rows for which STDistance returns NULL must be filtered out. Let’s start from the top. 1. Needs a spatial index on one of the columns that’s in the STDistance call. Yup, got the index. 2. No ‘PERCENT’. Yeah, I don’t have that. 3. The WHERE clause needs to use STDistance(). Ok, but I’m not filtering, so that should be fine. 4. Yeah, I don’t have multiple predicates. 5. The first expression in the ORDER BY is my distance, that’s fine. 6. Sort order is ASC, because otherwise we’d be starting with the ones that are furthest away, and that’s tricky. 7. All the rows for which STDistance returns NULL must be filtered out. But I don’t have any NULL values, so that shouldn’t affect me either. ...but something’s wrong. I do actually need to satisfy #3. And I do need to make sure #7 is being handled properly, because there are some situations (eg, differing SRIDs) where STDistance can return NULL. It says so at http://msdn.microsoft.com/en-us/library/bb933808.aspx – “STDistance() always returns null if the spatial reference IDs (SRIDs) of the geography instances do not match.” So if I simply make sure that I’m filtering out the rows that return NULL… …then it’s blindingly fast, I get the right results, and I’ve got the complex-but-brilliant plan that I wanted. It just wasn’t overly intuitive, despite being documented. @rob_farley

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  • C#/.NET Little Wonders: The EventHandler and EventHandler&lt;TEventArgs&gt; delegates

    - by James Michael Hare
    Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. In the last two weeks, we examined the Action family of delegates (and delegates in general), and the Func family of delegates and how they can be used to support generic, reusable algorithms and classes. So this week, we are going to look at a handy pair of delegates that can be used to eliminate the need for defining custom delegates when creating events: the EventHandler and EventHandler<TEventArgs> delegates. Events and delegates Before we begin, let’s quickly consider events in .NET.  According to the MSDN: An event in C# is a way for a class to provide notifications to clients of that class when some interesting thing happens to an object. So, basically, you can create an event in a type so that users of that type can subscribe to notifications of things of interest.  How is this different than some of the delegate programming that we talked about in the last two weeks?  Well, you can think of an event as a special access modifier on a delegate.  Some differences between the two are: Events are a special access case of delegates They behave much like delegates instances inside the type they are declared in, but outside of that type they can only be (un)subscribed to. Events can specify add/remove behavior explicitly If you want to do additional work when someone subscribes or unsubscribes to an event, you can specify the add and remove actions explicitly. Events have access modifiers, but these only specify the access level of those who can (un)subscribe A public event, for example, means anyone can (un)subscribe, but it does not mean that anyone can raise (invoke) the event directly.  Events can only be raised by the type that contains them In contrast, if a delegate is visible, it can be invoked outside of the object (not even in a sub-class!). Events tend to be for notifications only, and should be treated as optional Semantically speaking, events typically don’t perform work on the the class directly, but tend to just notify subscribers when something of note occurs. My basic rule-of-thumb is that if you are just wanting to notify any listeners (who may or may not care) that something has happened, use an event.  However, if you want the caller to provide some function to perform to direct the class about how it should perform work, make it a delegate. Declaring events using custom delegates To declare an event in a type, we simply use the event keyword and specify its delegate type.  For example, let’s say you wanted to create a new TimeOfDayTimer that triggers at a given time of the day (as opposed to on an interval).  We could write something like this: 1: public delegate void TimeOfDayHandler(object source, ElapsedEventArgs e); 2:  3: // A timer that will fire at time of day each day. 4: public class TimeOfDayTimer : IDisposable 5: { 6: // Event that is triggered at time of day. 7: public event TimeOfDayHandler Elapsed; 8:  9: // ... 10: } The first thing to note is that the event is a delegate type, which tells us what types of methods may subscribe to it.  The second thing to note is the signature of the event handler delegate, according to the MSDN: The standard signature of an event handler delegate defines a method that does not return a value, whose first parameter is of type Object and refers to the instance that raises the event, and whose second parameter is derived from type EventArgs and holds the event data. If the event does not generate event data, the second parameter is simply an instance of EventArgs. Otherwise, the second parameter is a custom type derived from EventArgs and supplies any fields or properties needed to hold the event data. So, in a nutshell, the event handler delegates should return void and take two parameters: An object reference to the object that raised the event. An EventArgs (or a subclass of EventArgs) reference to event specific information. Even if your event has no additional information to provide, you are still expected to provide an EventArgs instance.  In this case, feel free to pass the EventArgs.Empty singleton instead of creating new instances of EventArgs (to avoid generating unneeded memory garbage). The EventHandler delegate Because many events have no additional information to pass, and thus do not require custom EventArgs, the signature of the delegates for subscribing to these events is typically: 1: // always takes an object and an EventArgs reference 2: public delegate void EventHandler(object sender, EventArgs e) It would be insane to recreate this delegate for every class that had a basic event with no additional event data, so there already exists a delegate for you called EventHandler that has this very definition!  Feel free to use it to define any events which supply no additional event information: 1: public class Cache 2: { 3: // event that is raised whenever the cache performs a cleanup 4: public event EventHandler OnCleanup; 5:  6: // ... 7: } This will handle any event with the standard EventArgs (no additional information).  But what of events that do need to supply additional information?  Does that mean we’re out of luck for subclasses of EventArgs?  That’s where the generic for of EventHandler comes into play… The generic EventHandler<TEventArgs> delegate Starting with the introduction of generics in .NET 2.0, we have a generic delegate called EventHandler<TEventArgs>.  Its signature is as follows: 1: public delegate void EventHandler<TEventArgs>(object sender, TEventArgs e) 2: where TEventArgs : EventArgs This is similar to EventHandler except it has been made generic to support the more general case.  Thus, it will work for any delegate where the first argument is an object (the sender) and the second argument is a class derived from EventArgs (the event data). For example, let’s say we wanted to create a message receiver, and we wanted it to have a few events such as OnConnected that will tell us when a connection is established (probably with no additional information) and OnMessageReceived that will tell us when a new message arrives (probably with a string for the new message text). So for OnMessageReceived, our MessageReceivedEventArgs might look like this: 1: public sealed class MessageReceivedEventArgs : EventArgs 2: { 3: public string Message { get; set; } 4: } And since OnConnected needs no event argument type defined, our class might look something like this: 1: public class MessageReceiver 2: { 3: // event that is called when the receiver connects with sender 4: public event EventHandler OnConnected; 5:  6: // event that is called when a new message is received. 7: public event EventHandler<MessageReceivedEventArgs> OnMessageReceived; 8:  9: // ... 10: } Notice, nowhere did we have to define a delegate to fit our event definition, the EventHandler and generic EventHandler<TEventArgs> delegates fit almost anything we’d need to do with events. Sidebar: Thread-safety and raising an event When the time comes to raise an event, we should always check to make sure there are subscribers, and then only raise the event if anyone is subscribed.  This is important because if no one is subscribed to the event, then the instance will be null and we will get a NullReferenceException if we attempt to raise the event. 1: // This protects against NullReferenceException... or does it? 2: if (OnMessageReceived != null) 3: { 4: OnMessageReceived(this, new MessageReceivedEventArgs(aMessage)); 5: } The above code seems to handle the null reference if no one is subscribed, but there’s a problem if this is being used in multi-threaded environments.  For example, assume we have thread A which is about to raise the event, and it checks and clears the null check and is about to raise the event.  However, before it can do that thread B unsubscribes to the event, which sets the delegate to null.  Now, when thread A attempts to raise the event, this causes the NullReferenceException that we were hoping to avoid! To counter this, the simplest best-practice method is to copy the event (just a multicast delegate) to a temporary local variable just before we raise it.  Since we are inside the class where this event is being raised, we can copy it to a local variable like this, and it will protect us from multi-threading since multicast delegates are immutable and assignments are atomic: 1: // always make copy of the event multi-cast delegate before checking 2: // for null to avoid race-condition between the null-check and raising it. 3: var handler = OnMessageReceived; 4: 5: if (handler != null) 6: { 7: handler(this, new MessageReceivedEventArgs(aMessage)); 8: } The very slight trade-off is that it’s possible a class may get an event after it unsubscribes in a multi-threaded environment, but this is a small risk and classes should be prepared for this possibility anyway.  For a more detailed discussion on this, check out this excellent Eric Lippert blog post on Events and Races. Summary Generic delegates give us a lot of power to make generic algorithms and classes, and the EventHandler delegate family gives us the flexibility to create events easily, without needing to redefine delegates over and over.  Use them whenever you need to define events with or without specialized EventArgs.   Tweet Technorati Tags: .NET, C#, CSharp, Little Wonders, Generics, Delegates, EventHandler

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  • Hello Operator, My Switch Is Bored

    - by Paul White
    This is a post for T-SQL Tuesday #43 hosted by my good friend Rob Farley. The topic this month is Plan Operators. I haven’t taken part in T-SQL Tuesday before, but I do like to write about execution plans, so this seemed like a good time to start. This post is in two parts. The first part is primarily an excuse to use a pretty bad play on words in the title of this blog post (if you’re too young to know what a telephone operator or a switchboard is, I hate you). The second part of the post looks at an invisible query plan operator (so to speak). 1. My Switch Is Bored Allow me to present the rare and interesting execution plan operator, Switch: Books Online has this to say about Switch: Following that description, I had a go at producing a Fast Forward Cursor plan that used the TOP operator, but had no luck. That may be due to my lack of skill with cursors, I’m not too sure. The only application of Switch in SQL Server 2012 that I am familiar with requires a local partitioned view: CREATE TABLE dbo.T1 (c1 int NOT NULL CHECK (c1 BETWEEN 00 AND 24)); CREATE TABLE dbo.T2 (c1 int NOT NULL CHECK (c1 BETWEEN 25 AND 49)); CREATE TABLE dbo.T3 (c1 int NOT NULL CHECK (c1 BETWEEN 50 AND 74)); CREATE TABLE dbo.T4 (c1 int NOT NULL CHECK (c1 BETWEEN 75 AND 99)); GO CREATE VIEW V1 AS SELECT c1 FROM dbo.T1 UNION ALL SELECT c1 FROM dbo.T2 UNION ALL SELECT c1 FROM dbo.T3 UNION ALL SELECT c1 FROM dbo.T4; Not only that, but it needs an updatable local partitioned view. We’ll need some primary keys to meet that requirement: ALTER TABLE dbo.T1 ADD CONSTRAINT PK_T1 PRIMARY KEY (c1);   ALTER TABLE dbo.T2 ADD CONSTRAINT PK_T2 PRIMARY KEY (c1);   ALTER TABLE dbo.T3 ADD CONSTRAINT PK_T3 PRIMARY KEY (c1);   ALTER TABLE dbo.T4 ADD CONSTRAINT PK_T4 PRIMARY KEY (c1); We also need an INSERT statement that references the view. Even more specifically, to see a Switch operator, we need to perform a single-row insert (multi-row inserts use a different plan shape): INSERT dbo.V1 (c1) VALUES (1); And now…the execution plan: The Constant Scan manufactures a single row with no columns. The Compute Scalar works out which partition of the view the new value should go in. The Assert checks that the computed partition number is not null (if it is, an error is returned). The Nested Loops Join executes exactly once, with the partition id as an outer reference (correlated parameter). The Switch operator checks the value of the parameter and executes the corresponding input only. If the partition id is 0, the uppermost Clustered Index Insert is executed, adding a row to table T1. If the partition id is 1, the next lower Clustered Index Insert is executed, adding a row to table T2…and so on. In case you were wondering, here’s a query and execution plan for a multi-row insert to the view: INSERT dbo.V1 (c1) VALUES (1), (2); Yuck! An Eager Table Spool and four Filters! I prefer the Switch plan. My guess is that almost all the old strategies that used a Switch operator have been replaced over time, using things like a regular Concatenation Union All combined with Start-Up Filters on its inputs. Other new (relative to the Switch operator) features like table partitioning have specific execution plan support that doesn’t need the Switch operator either. This feels like a bit of a shame, but perhaps it is just nostalgia on my part, it’s hard to know. Please do let me know if you encounter a query that can still use the Switch operator in 2012 – it must be very bored if this is the only possible modern usage! 2. Invisible Plan Operators The second part of this post uses an example based on a question Dave Ballantyne asked using the SQL Sentry Plan Explorer plan upload facility. If you haven’t tried that yet, make sure you’re on the latest version of the (free) Plan Explorer software, and then click the Post to SQLPerformance.com button. That will create a site question with the query plan attached (which can be anonymized if the plan contains sensitive information). Aaron Bertrand and I keep a close eye on questions there, so if you have ever wanted to ask a query plan question of either of us, that’s a good way to do it. The problem The issue I want to talk about revolves around a query issued against a calendar table. The script below creates a simplified version and adds 100 years of per-day information to it: USE tempdb; GO CREATE TABLE dbo.Calendar ( dt date NOT NULL, isWeekday bit NOT NULL, theYear smallint NOT NULL,   CONSTRAINT PK__dbo_Calendar_dt PRIMARY KEY CLUSTERED (dt) ); GO -- Monday is the first day of the week for me SET DATEFIRST 1;   -- Add 100 years of data INSERT dbo.Calendar WITH (TABLOCKX) (dt, isWeekday, theYear) SELECT CA.dt, isWeekday = CASE WHEN DATEPART(WEEKDAY, CA.dt) IN (6, 7) THEN 0 ELSE 1 END, theYear = YEAR(CA.dt) FROM Sandpit.dbo.Numbers AS N CROSS APPLY ( VALUES (DATEADD(DAY, N.n - 1, CONVERT(date, '01 Jan 2000', 113))) ) AS CA (dt) WHERE N.n BETWEEN 1 AND 36525; The following query counts the number of weekend days in 2013: SELECT Days = COUNT_BIG(*) FROM dbo.Calendar AS C WHERE theYear = 2013 AND isWeekday = 0; It returns the correct result (104) using the following execution plan: The query optimizer has managed to estimate the number of rows returned from the table exactly, based purely on the default statistics created separately on the two columns referenced in the query’s WHERE clause. (Well, almost exactly, the unrounded estimate is 104.289 rows.) There is already an invisible operator in this query plan – a Filter operator used to apply the WHERE clause predicates. We can see it by re-running the query with the enormously useful (but undocumented) trace flag 9130 enabled: Now we can see the full picture. The whole table is scanned, returning all 36,525 rows, before the Filter narrows that down to just the 104 we want. Without the trace flag, the Filter is incorporated in the Clustered Index Scan as a residual predicate. It is a little bit more efficient than using a separate operator, but residual predicates are still something you will want to avoid where possible. The estimates are still spot on though: Anyway, looking to improve the performance of this query, Dave added the following filtered index to the Calendar table: CREATE NONCLUSTERED INDEX Weekends ON dbo.Calendar(theYear) WHERE isWeekday = 0; The original query now produces a much more efficient plan: Unfortunately, the estimated number of rows produced by the seek is now wrong (365 instead of 104): What’s going on? The estimate was spot on before we added the index! Explanation You might want to grab a coffee for this bit. Using another trace flag or two (8606 and 8612) we can see that the cardinality estimates were exactly right initially: The highlighted information shows the initial cardinality estimates for the base table (36,525 rows), the result of applying the two relational selects in our WHERE clause (104 rows), and after performing the COUNT_BIG(*) group by aggregate (1 row). All of these are correct, but that was before cost-based optimization got involved :) Cost-based optimization When cost-based optimization starts up, the logical tree above is copied into a structure (the ‘memo’) that has one group per logical operation (roughly speaking). The logical read of the base table (LogOp_Get) ends up in group 7; the two predicates (LogOp_Select) end up in group 8 (with the details of the selections in subgroups 0-6). These two groups still have the correct cardinalities as trace flag 8608 output (initial memo contents) shows: During cost-based optimization, a rule called SelToIdxStrategy runs on group 8. It’s job is to match logical selections to indexable expressions (SARGs). It successfully matches the selections (theYear = 2013, is Weekday = 0) to the filtered index, and writes a new alternative into the memo structure. The new alternative is entered into group 8 as option 1 (option 0 was the original LogOp_Select): The new alternative is to do nothing (PhyOp_NOP = no operation), but to instead follow the new logical instructions listed below the NOP. The LogOp_GetIdx (full read of an index) goes into group 21, and the LogOp_SelectIdx (selection on an index) is placed in group 22, operating on the result of group 21. The definition of the comparison ‘the Year = 2013’ (ScaOp_Comp downwards) was already present in the memo starting at group 2, so no new memo groups are created for that. New Cardinality Estimates The new memo groups require two new cardinality estimates to be derived. First, LogOp_Idx (full read of the index) gets a predicted cardinality of 10,436. This number comes from the filtered index statistics: DBCC SHOW_STATISTICS (Calendar, Weekends) WITH STAT_HEADER; The second new cardinality derivation is for the LogOp_SelectIdx applying the predicate (theYear = 2013). To get a number for this, the cardinality estimator uses statistics for the column ‘theYear’, producing an estimate of 365 rows (there are 365 days in 2013!): DBCC SHOW_STATISTICS (Calendar, theYear) WITH HISTOGRAM; This is where the mistake happens. Cardinality estimation should have used the filtered index statistics here, to get an estimate of 104 rows: DBCC SHOW_STATISTICS (Calendar, Weekends) WITH HISTOGRAM; Unfortunately, the logic has lost sight of the link between the read of the filtered index (LogOp_GetIdx) in group 22, and the selection on that index (LogOp_SelectIdx) that it is deriving a cardinality estimate for, in group 21. The correct cardinality estimate (104 rows) is still present in the memo, attached to group 8, but that group now has a PhyOp_NOP implementation. Skipping over the rest of cost-based optimization (in a belated attempt at brevity) we can see the optimizer’s final output using trace flag 8607: This output shows the (incorrect, but understandable) 365 row estimate for the index range operation, and the correct 104 estimate still attached to its PhyOp_NOP. This tree still has to go through a few post-optimizer rewrites and ‘copy out’ from the memo structure into a tree suitable for the execution engine. One step in this process removes PhyOp_NOP, discarding its 104-row cardinality estimate as it does so. To finish this section on a more positive note, consider what happens if we add an OVER clause to the query aggregate. This isn’t intended to be a ‘fix’ of any sort, I just want to show you that the 104 estimate can survive and be used if later cardinality estimation needs it: SELECT Days = COUNT_BIG(*) OVER () FROM dbo.Calendar AS C WHERE theYear = 2013 AND isWeekday = 0; The estimated execution plan is: Note the 365 estimate at the Index Seek, but the 104 lives again at the Segment! We can imagine the lost predicate ‘isWeekday = 0’ as sitting between the seek and the segment in an invisible Filter operator that drops the estimate from 365 to 104. Even though the NOP group is removed after optimization (so we don’t see it in the execution plan) bear in mind that all cost-based choices were made with the 104-row memo group present, so although things look a bit odd, it shouldn’t affect the optimizer’s plan selection. I should also mention that we can work around the estimation issue by including the index’s filtering columns in the index key: CREATE NONCLUSTERED INDEX Weekends ON dbo.Calendar(theYear, isWeekday) WHERE isWeekday = 0 WITH (DROP_EXISTING = ON); There are some downsides to doing this, including that changes to the isWeekday column may now require Halloween Protection, but that is unlikely to be a big problem for a static calendar table ;)  With the updated index in place, the original query produces an execution plan with the correct cardinality estimation showing at the Index Seek: That’s all for today, remember to let me know about any Switch plans you come across on a modern instance of SQL Server! Finally, here are some other posts of mine that cover other plan operators: Segment and Sequence Project Common Subexpression Spools Why Plan Operators Run Backwards Row Goals and the Top Operator Hash Match Flow Distinct Top N Sort Index Spools and Page Splits Singleton and Range Seeks Bitmaps Hash Join Performance Compute Scalar © 2013 Paul White – All Rights Reserved Twitter: @SQL_Kiwi

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  • LINQ: Enhancing Distinct With The PredicateEqualityComparer

    - by Paulo Morgado
    Today I was writing a LINQ query and I needed to select distinct values based on a comparison criteria. Fortunately, LINQ’s Distinct method allows an equality comparer to be supplied, but, unfortunately, sometimes, this means having to write custom equality comparer. Because I was going to need more than one equality comparer for this set of tools I was building, I decided to build a generic equality comparer that would just take a custom predicate. Something like this: public class PredicateEqualityComparer<T> : EqualityComparer<T> { private Func<T, T, bool> predicate; public PredicateEqualityComparer(Func<T, T, bool> predicate) : base() { this.predicate = predicate; } public override bool Equals(T x, T y) { if (x != null) { return ((y != null) && this.predicate(x, y)); } if (y != null) { return false; } return true; } public override int GetHashCode(T obj) { if (obj == null) { return 0; } return obj.GetHashCode(); } } Now I can write code like this: .Distinct(new PredicateEqualityComparer<Item>((x, y) => x.Field == y.Field)) But I felt that I’d lost all conciseness and expressiveness of LINQ and it doesn’t support anonymous types. So I came up with another Distinct extension method: public static IEnumerable<TSource> Distinct<TSource>(this IEnumerable<TSource> source, Func<TSource, TSource, bool> predicate) { return source.Distinct(new PredicateEqualityComparer<TSource>(predicate)); } And the query is now written like this: .Distinct((x, y) => x.Field == y.Field) Looks a lot better, doesn’t it?

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  • perl hide system output

    - by Chris
    Using perl 5.8.8 on linux, need the output of a perl 'system' command to be hidden. The command in my code is : system("wget", "$url", "-Omy_folder/$date-$target.html", "--user-agent=$useragent"); I've tried using " /dev/null 2&1" in different places in the system command, like this- system("wget", "$url", "-Omy_folder/$date-$target.html", "--user-agent=$useragent"," /dev/null 2&1"); Can anyone help me with where the redirection to /dev/null should be?

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  • I can't scroll my tilemap ... HELP!

    - by Sri Harsha Chilakapati
    Hello and I'm trying to make my own game engine in Java. I have completed all the necessary ones but I can't figure it out with the TileGame class. It just can't scroll. Also there are no exceptions. Here I'm listing the code. TileGame.java @Override public void draw(Graphics2D g) { if (back!=null){ back.render(g); } if (follower!=null){ follower.render(g); follower.draw(g); } for (int i=0; i<actors.size(); i++){ Actor actor = actors.get(i); if (actor!=follower&&getVisibleRect().intersects(actor.getBounds())){ g.drawImage(actor.getAnimation().getFrameImage(), actor.x - OffSetX, actor.y - OffSetY, null); actor.draw(g); } } } /** * This method returns the visible rectangle * @return The visible rectangle */ public Rectangle getVisibleRect(){ return new Rectangle(OffSetX, OffSetY, global.WIDTH, global.HEIGHT); } @Override public void update(){ if (follower!=null){ if (scrollHorizontally){ OffSetX = global.WIDTH/2 - Math.round((float)follower.x) - tileSize; OffSetX = Math.min(OffSetX, 0); OffSetX = Math.max(OffSetX, global.WIDTH - mapWidth); } if (scrollVertically){ OffSetY = global.HEIGHT/2 - Math.round((float)follower.y) - tileSize; OffSetY = Math.min(OffSetY, 0); OffSetY = Math.max(OffSetY, global.HEIGHT - mapHeight); } } for (int i=0; i<actors.size(); i++){ Actor actor1 = actors.get(i); if (getVisibleRect().contains(actor1.x, actor1.y)){ actor1.update(); for (int j=0; j<actors.size(); j++){ Actor actor2 = actors.get(j); if (actor1.isCollidingWith(actor2)){ actor1.collision(actor2); actor2.collision(actor1); } } } } } but the problem is that all the actors are working, but it just won't scroll. Help Please.. Thanks in Advance.

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  • Making a Statement: How to retrieve the T-SQL statement that caused an event

    - by extended_events
    If you’ve done any troubleshooting of T-SQL, you know that sooner or later, probably sooner, you’re going to want to take a look at the actual statements you’re dealing with. In extended events we offer an action (See the BOL topic that covers Extended Events Objects for a description of actions) named sql_text that seems like it is just the ticket. Well…not always – sounds like a good reason for a blog post. When is a statement not THE statement? The sql_text action returns the same information that is returned from DBCC INPUTBUFFER, which may or may not be what you want. For example, if you execute a stored procedure, the sql_text action will return something along the lines of “EXEC sp_notwhatiwanted” assuming that is the statement you sent from the client. Often times folks would like something more specific, like the actual statements that are being run from within the stored procedure or batch. Enter the stack Extended events offers another action, this one with the descriptive name of tsql_stack, that includes the sql_handle and offset information about the statements being run when an event occurs. With the sql_handle and offset values you can retrieve the specific statement you seek using the DMV dm_exec_sql_statement. The BOL topic for dm_exec_sql_statement provides an example for how to extract this information, so I’ll cover the gymnastics required to get the sql_handle and offset values out of the tsql_stack data collected by the action. I’m the first to admit that this isn’t pretty, but this is what we have in SQL Server 2008 and 2008 R2. We will be making it easier to get statement level information in the next major release of SQL Server. The sample code For this example I have a stored procedure that includes multiple statements and I have a need to differentiate between those two statements in my tracing. I’m going to track two events: module_end tracks the completion of the stored procedure execution and sp_statement_completed tracks the execution of each statement within a stored procedure. I’m adding the tsql_stack events (since that’s the topic of this post) and the sql_text action for comparison sake. (If you have questions about creating event sessions, check out Pedro’s post Introduction to Extended Events.) USE AdventureWorks2008GO -- Test SPCREATE PROCEDURE sp_multiple_statementsASSELECT 'This is the first statement'SELECT 'this is the second statement'GO -- Create a session to look at the spCREATE EVENT SESSION track_sprocs ON SERVERADD EVENT sqlserver.module_end (ACTION (sqlserver.tsql_stack, sqlserver.sql_text)),ADD EVENT sqlserver.sp_statement_completed (ACTION (sqlserver.tsql_stack, sqlserver.sql_text))ADD TARGET package0.ring_bufferWITH (MAX_DISPATCH_LATENCY = 1 SECONDS)GO -- Start the sessionALTER EVENT SESSION track_sprocs ON SERVERSTATE = STARTGO -- Run the test procedureEXEC sp_multiple_statementsGO -- Stop collection of events but maintain ring bufferALTER EVENT SESSION track_sprocs ON SERVERDROP EVENT sqlserver.module_end,DROP EVENT sqlserver.sp_statement_completedGO Aside: Altering the session to drop the events is a neat little trick that allows me to stop collection of events while keeping in-memory targets such as the ring buffer available for use. If you stop the session the in-memory target data is lost. Now that we’ve collected some events related to running the stored procedure, we need to do some processing of the data. I’m going to do this in multiple steps using temporary tables so you can see what’s going on; kind of like having to “show your work” on a math test. The first step is to just cast the target data into XML so I can work with it. After that you can pull out the interesting columns, for our purposes I’m going to limit the output to just the event name, object name, stack and sql text. You can see that I’ve don a second CAST, this time of the tsql_stack column, so that I can further process this data. -- Store the XML data to a temp tableSELECT CAST( t.target_data AS XML) xml_dataINTO #xml_event_dataFROM sys.dm_xe_sessions s INNER JOIN sys.dm_xe_session_targets t    ON s.address = t.event_session_addressWHERE s.name = 'track_sprocs' SELECT * FROM #xml_event_data -- Parse the column data out of the XML blockSELECT    event_xml.value('(./@name)', 'varchar(100)') as [event_name],    event_xml.value('(./data[@name="object_name"]/value)[1]', 'varchar(255)') as [object_name],    CAST(event_xml.value('(./action[@name="tsql_stack"]/value)[1]','varchar(MAX)') as XML) as [stack_xml],    event_xml.value('(./action[@name="sql_text"]/value)[1]', 'varchar(max)') as [sql_text]INTO #event_dataFROM #xml_event_data    CROSS APPLY xml_data.nodes('//event') n (event_xml) SELECT * FROM #event_data event_name object_name stack_xml sql_text sp_statement_completed NULL <frame level="1" handle="0x03000500D0057C1403B79600669D00000100000000000000" line="4" offsetStart="94" offsetEnd="172" /><frame level="2" handle="0x01000500CF3F0331B05EC084000000000000000000000000" line="1" offsetStart="0" offsetEnd="-1" /> EXEC sp_multiple_statements sp_statement_completed NULL <frame level="1" handle="0x03000500D0057C1403B79600669D00000100000000000000" line="6" offsetStart="174" offsetEnd="-1" /><frame level="2" handle="0x01000500CF3F0331B05EC084000000000000000000000000" line="1" offsetStart="0" offsetEnd="-1" /> EXEC sp_multiple_statements module_end sp_multiple_statements <frame level="1" handle="0x03000500D0057C1403B79600669D00000100000000000000" line="0" offsetStart="0" offsetEnd="0" /><frame level="2" handle="0x01000500CF3F0331B05EC084000000000000000000000000" line="1" offsetStart="0" offsetEnd="-1" /> EXEC sp_multiple_statements After parsing the columns it’s easier to see what is recorded. You can see that I got back two sp_statement_completed events, which makes sense given the test procedure I’m running, and I got back a single module_end for the entire statement. As described, the sql_text isn’t telling me what I really want to know for the first two events so a little extra effort is required. -- Parse the tsql stack information into columnsSELECT    event_name,    object_name,    frame_xml.value('(./@level)', 'int') as [frame_level],    frame_xml.value('(./@handle)', 'varchar(MAX)') as [sql_handle],    frame_xml.value('(./@offsetStart)', 'int') as [offset_start],    frame_xml.value('(./@offsetEnd)', 'int') as [offset_end]INTO #stack_data    FROM #event_data        CROSS APPLY    stack_xml.nodes('//frame') n (frame_xml)    SELECT * from #stack_data event_name object_name frame_level sql_handle offset_start offset_end sp_statement_completed NULL 1 0x03000500D0057C1403B79600669D00000100000000000000 94 172 sp_statement_completed NULL 2 0x01000500CF3F0331B05EC084000000000000000000000000 0 -1 sp_statement_completed NULL 1 0x03000500D0057C1403B79600669D00000100000000000000 174 -1 sp_statement_completed NULL 2 0x01000500CF3F0331B05EC084000000000000000000000000 0 -1 module_end sp_multiple_statements 1 0x03000500D0057C1403B79600669D00000100000000000000 0 0 module_end sp_multiple_statements 2 0x01000500CF3F0331B05EC084000000000000000000000000 0 -1 Parsing out the stack information doubles the fun and I get two rows for each event. If you examine the stack from the previous table, you can see that each stack has two frames and my query is parsing each event into frames, so this is expected. There is nothing magic about the two frames, that’s just how many I get for this example, it could be fewer or more depending on your statements. The key point here is that I now have a sql_handle and the offset values for those handles, so I can use dm_exec_sql_statement to get the actual statement. Just a reminder, this DMV can only return what is in the cache – if you have old data it’s possible your statements have been ejected from the cache. “Old” is a relative term when talking about caches and can be impacted by server load and how often your statement is actually used. As with most things in life, your mileage may vary. SELECT    qs.*,     SUBSTRING(st.text, (qs.offset_start/2)+1,         ((CASE qs.offset_end          WHEN -1 THEN DATALENGTH(st.text)         ELSE qs.offset_end         END - qs.offset_start)/2) + 1) AS statement_textFROM #stack_data AS qsCROSS APPLY sys.dm_exec_sql_text(CONVERT(varbinary(max),sql_handle,1)) AS st event_name object_name frame_level sql_handle offset_start offset_end statement_text sp_statement_completed NULL 1 0x03000500D0057C1403B79600669D00000100000000000000 94 172 SELECT 'This is the first statement' sp_statement_completed NULL 1 0x03000500D0057C1403B79600669D00000100000000000000 174 -1 SELECT 'this is the second statement' module_end sp_multiple_statements 1 0x03000500D0057C1403B79600669D00000100000000000000 0 0 C Now that looks more like what we were after, the statement_text field is showing the actual statement being run when the sp_statement_completed event occurs. You’ll notice that it’s back down to one row per event, what happened to frame 2? The short answer is, “I don’t know.” In SQL Server 2008 nothing is returned from dm_exec_sql_statement for the second frame and I believe this to be a bug; this behavior has changed in the next major release and I see the actual statement run from the client in frame 2. (In other words I see the same statement that is returned by the sql_text action  or DBCC INPUTBUFFER) There is also something odd going on with frame 1 returned from the module_end event; you can see that the offset values are both 0 and only the first letter of the statement is returned. It seems like the offset_end should actually be –1 in this case and I’m not sure why it’s not returning this correctly. This behavior is being investigated and will hopefully be corrected in the next major version. You can workaround this final oddity by ignoring the offsets and just returning the entire cached statement. SELECT    event_name,    sql_handle,    ts.textFROM #stack_data    CROSS APPLY sys.dm_exec_sql_text(CONVERT(varbinary(max),sql_handle,1)) as ts event_name sql_handle text sp_statement_completed 0x0300070025999F11776BAF006F9D00000100000000000000 CREATE PROCEDURE sp_multiple_statements AS SELECT 'This is the first statement' SELECT 'this is the second statement' sp_statement_completed 0x0300070025999F11776BAF006F9D00000100000000000000 CREATE PROCEDURE sp_multiple_statements AS SELECT 'This is the first statement' SELECT 'this is the second statement' module_end 0x0300070025999F11776BAF006F9D00000100000000000000 CREATE PROCEDURE sp_multiple_statements AS SELECT 'This is the first statement' SELECT 'this is the second statement' Obviously this gives more than you want for the sp_statement_completed events, but it’s the right information for module_end. I leave it to you to determine when this information is needed and use the workaround when appropriate. Aside: You might think it’s odd that I’m showing apparent bugs with my samples, but you’re going to see this behavior if you use this method, so you need to know about it.I’m all about transparency. Happy Eventing- Mike Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it!

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  • SVN do unnecessary chmod on .svn/tempfiles

    - by ???
    My working dir is on an TrueCrypt NTFS volume, with umask 000. So I can read/write on any files with no problem. But I can't do svn command on it, for example `svn update' shows error: svn: Can't set permissions on '.svn/tempfile.8.tmp': strace svn up gives: ... chmod("sbin/.svn/tempfile.2.tmp", 0770) = -1 EPERM (Operation not permitted) fcntl64(3, F_GETFL) = 0x2 (flags O_RDWR) fcntl64(3, F_SETFL, O_RDWR|O_NONBLOCK) = 0 write(3, "( failure ( ( 1 76:Can't set per"..., 172) = 172 fcntl64(3, F_GETFL) = 0x802 (flags O_RDWR|O_NONBLOCK) fcntl64(3, F_SETFL, O_RDWR) = 0 read(3, "( abort-edit ( ) ) ( failure ( ("..., 4096) = 191 gettimeofday({1276661368, 382789}, NULL) = 0 lstat64("sbin", {st_mode=S_IFDIR|0770, st_size=0, ...}) = 0 select(0, NULL, NULL, NULL, {0, 1000}) = 0 (Timeout) write(2, "svn: Can't set permissions on 's"..., 82svn: Can't set permissions on 'sbin/.svn/tempfile.2.tmp': Operation not permitted) = 82 close(3) = 0 So, the error occurred when svn chmod on some tmp files. But this is disallowed in the TrueCrypt volumes, and it's just unnecessary. Can I bypass the chmod lib calls when launch svn on TrueCrypt volumes?

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  • postgresql deleteing old tables

    - by BB
    I have a postgresql database which stores my radius connection information. What I want to do is only store a months worth of logs. How would I craft a sql statement that I can run from cron that would go and delete and rows that where older then a month? Format of the date in the table. that date is taken from acctstoptime collum Date format 2010-01-27 16:02:17-05 Format of the table in question. -- Table: radacct -- DROP TABLE radacct; CREATE TABLE radacct ( radacctid bigserial NOT NULL, acctsessionid character varying(32) NOT NULL, acctuniqueid character varying(32) NOT NULL, username character varying(253), groupname character varying(253), realm character varying(64), nasipaddress inet NOT NULL, nasportid character varying(15), nasporttype character varying(32), acctstarttime timestamp with time zone, acctstoptime timestamp with time zone, acctsessiontime bigint, acctauthentic character varying(32), connectinfo_start character varying(50), connectinfo_stop character varying(50), acctinputoctets bigint, acctoutputoctets bigint, calledstationid character varying(50), callingstationid character varying(50), acctterminatecause character varying(32), servicetype character varying(32), xascendsessionsvrkey character varying(10), framedprotocol character varying(32), framedipaddress inet, acctstartdelay integer, acctstopdelay integer, freesidestatus character varying(32), CONSTRAINT radacct_pkey PRIMARY KEY (radacctid) ) WITH (OIDS=FALSE); ALTER TABLE radacct OWNER TO radius; -- Index: freesidestatus -- DROP INDEX freesidestatus; CREATE INDEX freesidestatus ON radacct USING btree (freesidestatus); -- Index: radacct_active_user_idx -- DROP INDEX radacct_active_user_idx; CREATE INDEX radacct_active_user_idx ON radacct USING btree (username, nasipaddress, acctsessionid) WHERE acctstoptime IS NULL; -- Index: radacct_start_user_idx -- DROP INDEX radacct_start_user_idx; CREATE INDEX radacct_start_user_idx ON radacct USING btree (acctstarttime, username);

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  • Constructor vs setter validations

    - by Jimmy
    I have the following class : public class Project { private int id; private String name; public Project(int id, String name, Date creationDate, int fps, List<String> frames) { if(name == null ){ throw new NullPointerException("Name can't be null"); } if(id == 0 ){ throw new IllegalArgumentException("id can't be zero"); } this.name = name; this.id = id; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } } I have three questions: Do I use the class setters instead of setting the fields directly. One of the reason that I set it directly, is that in the code the setters are not final and they could be overridden. If the right way is to set it directly and I want to make sure that the name filed is not null always. Should I provide two checks, one in the constructor and one in the setter. I read in effective java that I should use NullPointerException for null parameters. Should I use IllegalArgumentException for other checks, like id in the example.

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  • Android device - C++ OpenGL 2: eglCreateWindowSurface invalid

    - by ThreaderSlash
    I am trying to debug and run OGLES on Native C++ in my Android device in order to implement a native 3D game for mobile smart phones. The point is that I got an error and see no reason for that. Here is the line from the code that the debugger complains: mSurface = eglCreateWindowSurface(mDisplay, lConfig, mApplication->window, NULL); And this is the error message: Invalid arguments ' Candidates are: void * eglCreateWindowSurface(void *, void *, unsigned long int, const int *) ' --x-- Here is the declaration: android_app* mApplication; EGLDisplay mDisplay; EGLint lFormat, lNumConfigs, lErrorResult; EGLConfig lConfig; // Defines display requirements. 16bits mode here. const EGLint lAttributes[] = { EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT, EGL_BLUE_SIZE, 5, EGL_GREEN_SIZE, 6, EGL_RED_SIZE, 5, EGL_SURFACE_TYPE, EGL_WINDOW_BIT, EGL_RENDER_BUFFER, EGL_BACK_BUFFER, EGL_NONE }; // Retrieves a display connection and initializes it. packt_Log_debug("Connecting to the display."); mDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY); if (mDisplay == EGL_NO_DISPLAY) goto ERROR; if (!eglInitialize(mDisplay, NULL, NULL)) goto ERROR; // Selects the first OpenGL configuration found. packt_Log_debug("Selecting a display config."); if(!eglChooseConfig(mDisplay, lAttributes, &lConfig, 1, &lNumConfigs) || (lNumConfigs <= 0)) goto ERROR; // Reconfigures the Android window with the EGL format. packt_Log_debug("Configuring window format."); if (!eglGetConfigAttrib(mDisplay, lConfig, EGL_NATIVE_VISUAL_ID, &lFormat)) goto ERROR; ANativeWindow_setBuffersGeometry(mApplication->window, 0, 0, lFormat); // Creates the display surface. packt_Log_debug("Initializing the display."); mSurface = eglCreateWindowSurface(mDisplay, lConfig, mApplication->window, NULL); --x-- Hope someone here can shed some light on it.

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  • Animating Tile with Blitting taking up Memory.

    - by Kid
    I am trying to animate a specific tile in my 2d Array, using blitting. The animation consists of three different 16x16 sprites in a tilesheet. Now that works perfect with the code below. BUT it's causing memory leakage. Every second the FlashPlayer is taking up +140 kb more in memory. What part of the following code could possibly cause the leak: //The variable Rectangle finds where on the 2d array we should clear the pixels //Fillrect follows up by setting alpha 0 at that spot before we copy in nxt Sprite //Tiletype is a variable that holds what kind of tile the next tile in animation is //(from tileSheet) //drawTile() gets Sprite from tilesheet and copyPixels it into right position on canvas public function animateSprite():void{ tileGround.bitmapData.lock(); if(anmArray[0].tileType > 42){ anmArray[0].tileType = 40; frameCount = 0; } var rect:Rectangle = new Rectangle(anmArray[0].xtile * ts, anmArray[0].ytile * ts, ts, ts); tileGround.bitmapData.fillRect(rect, 0); anmArray[0].tileType = 40 + frameCount; drawTile(anmArray[0].tileType, anmArray[0].xtile, anmArray[0].ytile); frameCount++; tileGround.bitmapData.unlock(); } public function drawTile(spriteType:int, xt:int, yt:int):void{ var tileSprite:Bitmap = getImageFromSheet(spriteType, ts); var rec:Rectangle = new Rectangle(0, 0, ts, ts); var pt:Point = new Point(xt * ts, yt * ts); tileGround.bitmapData.copyPixels(tileSprite.bitmapData, rec, pt, null, null, true); } public function getImageFromSheet(spriteType:int, size:int):Bitmap{ var sheetColumns:int = tSheet.width/ts; var col:int = spriteType % sheetColumns; var row:int = Math.floor(spriteType/sheetColumns); var rec:Rectangle = new Rectangle(col * ts, row * ts, size, size); var pt:Point = new Point(0,0); var correctTile:Bitmap = new Bitmap(new BitmapData(size, size, false, 0)); correctTile.bitmapData.copyPixels(tSheet, rec, pt, null, null, true); return correctTile; }

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  • postgresql deleteing old records from log tables

    - by Max
    I have a postgresql database which stores my radius connection information. What I want to do is only store a months worth of logs. How would I craft a sql statement that I can run from cron that would go and delete and rows that where older then a month? Format of the date in the table. that date is taken from acctstoptime collum Date format 2010-01-27 16:02:17-05 Format of the table in question. -- Table: radacct CREATE TABLE radacct ( radacctid bigserial NOT NULL, acctsessionid character varying(32) NOT NULL, acctuniqueid character varying(32) NOT NULL, username character varying(253), groupname character varying(253), realm character varying(64), nasipaddress inet NOT NULL, nasportid character varying(15), nasporttype character varying(32), acctstarttime timestamp with time zone, acctstoptime timestamp with time zone, acctsessiontime bigint, acctauthentic character varying(32), connectinfo_start character varying(50), connectinfo_stop character varying(50), acctinputoctets bigint, acctoutputoctets bigint, calledstationid character varying(50), callingstationid character varying(50), acctterminatecause character varying(32), servicetype character varying(32), xascendsessionsvrkey character varying(10), framedprotocol character varying(32), framedipaddress inet, acctstartdelay integer, acctstopdelay integer, freesidestatus character varying(32), CONSTRAINT radacct_pkey PRIMARY KEY (radacctid) ) WITH (OIDS=FALSE); ALTER TABLE radacct OWNER TO radius; -- Index: freesidestatus CREATE INDEX freesidestatus ON radacct USING btree (freesidestatus); -- Index: radacct_active_user_idx CREATE INDEX radacct_active_user_idx ON radacct USING btree (username, nasipaddress, acctsessionid) WHERE acctstoptime IS NULL; -- Index: radacct_start_user_idx CREATE INDEX radacct_start_user_idx ON radacct USING btree (acctstarttime, username);

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  • Steam (via Wine) crashes after login - any troubleshooting tips?

    - by new Thrall
    The Steam client crashes after I login. After submitting my credentials, Steam displays a dialog box informing me the client is 'connecting'. I then see the Steam main page and news page displayed for roughly a second or so before the client crashes. I'm running Ubuntu 10.10 (I think..what's the best way to verify? uname only displays Linux) which I've installed on a usb flash drive using a capser-rw file for persistence. wine-1.3.14 I'm not sure how to troubleshoot. How do I identify if the problem is with wine or steam or the video card driver, or what? Any ideas? hardware: motherboard: ECS Elitegroup 945GCT-M sound: integrated audio video: ATI Radeon X1950 console output: ubuntu@ubuntu:~/.wine/drive_c/Program Files/Steam$ wine Steam.exe fixme:process:GetLogicalProcessorInformation ((nil),0x32e488): stub fixme:process:GetLogicalProcessorInformation (0x1010c00,0x32e488): stub fixme:process:SetProcessShutdownParameters (00000100, 00000000): partial stub. fixme:urlmon:CoInternetSetFeatureEnabled 5, 0x00000002, 1, stub fixme:urlmon:CoInternetSetFeatureEnabled 10, 0x00000002, 1, stub fixme:dwmapi:DwmSetWindowAttribute (0x1009a, 2, 0x32d334, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x1009a, 3, 0x32d338, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x1009a, 4, 0x32d33c, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x100a2, 2, 0x32d964, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x100a2, 3, 0x32d968, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x100a2, 4, 0x32d96c, 4) stub err:ole:CoGetClassObject class {77f10cf0-3db5-4966-b520-b7c54fd35ed6} not registered err:ole:CoGetClassObject no class object {77f10cf0-3db5-4966-b520-b7c54fd35ed6} could be created for context 0x1 fixme:wbemprox:wbem_locator_ConnectServer 0x1ab5f0, L"ROOT\CIMV2", (null), (null), (null), 0x00000080, (null), (nil), 0x42bbee8) fixme:dwmapi:DwmSetWindowAttribute (0x100ae, 2, 0x32d8cc, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x100ae, 3, 0x32d8d0, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x100ae, 4, 0x32d8d4, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x100b6, 2, 0x32d80c, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x100b6, 3, 0x32d810, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x100b6, 4, 0x32d814, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x100c0, 2, 0x32d2e4, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x100c0, 3, 0x32d2e8, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x100c0, 4, 0x32d2ec, 4) stub fixme:winhttp:WinHttpGetIEProxyConfigForCurrentUser returning no proxy used fixme:dwmapi:DwmSetWindowAttribute (0x100dc, 2, 0x32d94c, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x100dc, 3, 0x32d950, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x100dc, 4, 0x32d954, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x10118, 2, 0x32da8c, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x10118, 3, 0x32da90, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x10118, 4, 0x32da94, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x10122, 2, 0x32d514, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x10122, 3, 0x32d518, 4) stub fixme:dwmapi:DwmSetWindowAttribute (0x10122, 4, 0x32d51c, 4) stub fixme:dbghelp:elf_search_auxv can't find symbol in module

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  • How I use RegExp in my Java program? [migrated]

    - by MIH1406
    I have the following string examples: 00001 1 12 123 00002 3 7 321 00003 99 23 332 00004 192 50 912 In a separate text file. Numbers are separated by tabs not spaces. I tried to read the file and print each line if it matches a given RegExp, but I could not find the suitable RegExp for these lines. private static void readFile() { String fileName = "processes.lst"; FileReader file = null; String result = ""; try { file = new FileReader(fileName); BufferedReader reader = new BufferedReader(file); String line = null; String regEx = "[0-9]\t[0-9]\t[0-9]\t[0-9]"; while((line = reader.readLine()) != null) { if(line.matches(regEx)) { result += "\n" + line; } } } catch(Exception e) { System.out.println(e.getMessage()); } finally { if(file != null) try { file.close(); } catch(Exception e) { System.out.println(e.getMessage()); } } System.out.println(result); } I ended up without any string being printed!!

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  • Collection RemoveAll Extension Method

    - by João Angelo
    I had previously posted a RemoveAll extension method for the Dictionary<K,V> class, now it’s time to have one for the Collection<T> class. The signature is the same as in the corresponding method already available in List<T> and the implementation relies on the RemoveAt method to perform the actual removal of each element. Finally, here’s the code: public static class CollectionExtensions { /// <summary> /// Removes from the target collection all elements that match the specified predicate. /// </summary> /// <typeparam name="T">The type of elements in the target collection.</typeparam> /// <param name="collection">The target collection.</param> /// <param name="match">The predicate used to match elements.</param> /// <exception cref="ArgumentNullException"> /// The target collection is a null reference. /// <br />-or-<br /> /// The match predicate is a null reference. /// </exception> /// <returns>Returns the number of elements removed.</returns> public static int RemoveAll<T>(this Collection<T> collection, Predicate<T> match) { if (collection == null) throw new ArgumentNullException("collection"); if (match == null) throw new ArgumentNullException("match"); int count = 0; for (int i = collection.Count - 1; i >= 0; i--) { if (match(collection[i])) { collection.RemoveAt(i); count++; } } return count; } }

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  • Change the output format of zsh's time

    - by YGA
    Hi Folks, I've just switched to zsh. However, I really don't like how the time builtin command also outputs the command that it's timing. I much prefer the bash style output. Anyone know how to switch it over? Zsh: [casqa1:~/temp]$ time grep foo /dev/null /usr/local/gnu/bin/grep --color -i foo /dev/null 0.00s user 0.00s system 53% cpu 0.004 total Bash: [casqa1:~/temp]$ bash casqa1.nyc:~/temp> time grep foo /dev/null real 0.0 user 0.0 sys 0.0 Thanks, /YGA

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  • Backup database from default (unnamed) sql server instance with powershell.

    - by sparks
    Trying to connect to an instance of SQL Server 2008 on a server we'll call Sputnik. There are no firewalls in between the two devices. Right now I'm just trying to list databases [System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.SMO") | Out-Null [System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.SmoExtended") | Out-Null [System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.ConnectionInfo") | Out-Null [System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.SmoEnum") | Out-Null $servername = "Sputnik" $remoteServer = New-Object("Microsoft.SqlServer.Management.Smo.Server") $servername $remoteServer.databases The following error message occurs: The following exception was thrown when trying to enumerate the collection: "Failed to connect to server Sputnik.". At line:1 char:15 + $remoteServer. <<<< databases + CategoryInfo : NotSpecified: (:) [], ExtendedTypeSystemException + FullyQualifiedErrorId : ExceptionInGetEnumerator

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  • Syntax of passing lambda

    - by Astara
    Right now, I'm working on refactoring a program that calls its parts by polling to a more event-driven structure. I've created sched and task classes with the sced to become a base class of the current main loop. The tasks will be created for each meter so they can be called off of that instead of polling. Each of the events main calls are a type of meter that gather info and display it. When the program is coming up, all enabled meters get 'constructed' by a main-sub. In that sub, I want to store off the "this" pointer associated with the meter, as well as the common name for the "action routine. void MeterMaker::Meter_n_Task (Meter * newmeter,) { push(newmeter); // handle non-timed draw events Task t = new Task(now() + 0.5L); t.period={0,1U}; t.work_meter = newmeter; t.work = [&newmeter](){newmeter.checkevent();};<<--attempt at lambda t.flags = T_Repeat; t.enable_task(); _xos->sched_insert(t); } A sample call to it: Meter_n_Task(new CPUMeter(_xos, "CPU ")); 've made the scheduler a base class of the main routine (that handles the loop), and I've tried serveral variations to get the task class to be a base of the meter class, but keep running into roadblocks. It's alot like "whack-a-mole" -- pound in something to fix something one place, and then a new probl pops out elsewhere. Part of the problem, is that the sched.h file that is trying to hold the Task Q, includes the Task header file. The task file Wants to refer to the most "base", Meter class. The meter class pulls in the main class of the parent as it passes a copy of the parent to the children so they can access the draw routines in the parent. Two references in the task file are for the 'this' pointer of the meter and the meter's update sub (to be called via this). void *this_data= NULL; void (*this_func)() = NULL; Note -- I didn't really want to store these in the class, as I wanted to use a lamdba in that meter&task routine above to store a routine+context to be used to call the meter's action routine. Couldn't figure out the syntax. But am running into other syntax problems trying to store the pointers...such as g++: COMPILE lsched.cc In file included from meter.h:13:0, from ltask.h:17, from lsched.h:13, from lsched.cc:13: xosview.h:30:47: error: expected class-name before ‘{’ token class XOSView : public XWin, public Scheduler { Like above where it asks for a class, where the classname "Scheduler" is. !?!? Huh? That IS a class name. I keep going in circles with things that don't make sense... Ideally I'd get the lamba to work right in the Meter_n_Task routine at the top. I wanted to only store 1 pointer in the 'Task' class that was a pointer to my lambda that would have already captured the "this" value ... but couldn't get that syntax to work at all when I tried to start it into a var in the 'Task' class. This project, FWIW, is my teething project on the new C++... (of course it's simple!.. ;-))... I've made quite a bit of progress in other areas in the code, but this lambda syntax has me stumped...its at times like thse that I appreciate the ease of this type of operation in perl. Sigh. Not sure the best way to ask for help here, as this isn't a simple question. But thought I'd try!... ;-) Too bad I can't attach files to this Q.

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  • Game programming basics under Windows

    - by dreta
    I've been trying to learn some Windows programming using the Win32 API. Now, i'm used to working with the OS layer being abstracted away, mostly thanks to libraries like SFML or Allegro. Could you guys help me out and tell me if i'm thinking right here. The place for my gameloop is where i'm reading the messages? while (TRUE) { if (PeekMessage (&msg, NULL, 0, 0, PM_REMOVE)) { if (msg.message == WM_QUIT) break ; TranslateMessage (&msg) ; DispatchMessage (&msg) ; } else { //my game loop goes here } } Now the slightly bigger issue, that is, drawing. Do i run my drawing where i normaly do it, inside the game loop after the game logic? Or do i do it when WM_PAIN is being called and just call InvalidateRect (hwnd, NULL, TRUE); when i want to draw? This does feel weird, the WM_PAINT is a queued message, so i don't know for sure when it'll be called. So if i wanted to avoid this, do i just get the device handle inside the game loop and only ValidateRect (hwnd, NULL); in the WM_PAINT case (beside the ValidateRect (hwnd, NULL); called after drawing in the game loop)? Actually, now that i think about it, do i even need WM_PAINT in this situation or can i skip it and let DefWindowProc handle it (does it validate the screen if WM_PAINT isn't processed)? If this is any important, i'm setting up my code for OpenGL.

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  • How do you determine whether a website is a scam [closed]

    - by Tom
    What's the best way to determine if a website is a scam. For example, at first sight (no pun intended) the following website seems to be legitimate. But the price of the product is suspiciously low (all the reviews point to an RRP of approximately £1000). http://www.maxiargos.com/index.php/asus-zenbook-ux31e-dh72-13-3-inch-thin-and-light-ultrabook-silver-aluminum.html Another indication is the lack of SSL for the checkout page, and lack of useful information in the WHOIS record. Registration Service Provided By: TMDHOSTING Contact: +1.8665325635 Domain Name: MAXIARGOS.COM Registrant: PrivacyProtect.org Domain Admin ([email protected]) ID#10760, PO Box 16 Note - All Postal Mails Rejected, visit Privacyprotect.org Nobby Beach null,QLD 4218 AU Tel. +45.36946676 Creation Date: 09-Nov-2011 Expiration Date: 09-Nov-2012 Domain servers in listed order: ns1.tmdhosting410.com ns2.tmdhosting410.com Administrative Contact: PrivacyProtect.org Domain Admin ([email protected]) ID#10760, PO Box 16 Note - All Postal Mails Rejected, visit Privacyprotect.org Nobby Beach null,QLD 4218 AU Tel. +45.36946676 Technical Contact: PrivacyProtect.org Domain Admin ([email protected]) ID#10760, PO Box 16 Note - All Postal Mails Rejected, visit Privacyprotect.org Nobby Beach null,QLD 4218 AU Tel. +45.36946676 Billing Contact: PrivacyProtect.org Domain Admin ([email protected]) ID#10760, PO Box 16 Note - All Postal Mails Rejected, visit Privacyprotect.org Nobby Beach null,QLD 4218 AU Tel. +45.36946676

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  • My new favourite traceflag

    - by Dave Ballantyne
    As we are all aware, there are a number of traceflags.  Some documented, some semi-documented and some completely undocumented.  Here is one that is undocumented that Paul White(b|t) mentioned almost as an aside in one of his excellent blog posts. Much has been written about residual predicates and how a predicate can be pushed into a seek/scan operation.  This is a good thing to happen,  it does save a lot of processing from having to be done.  For the uninitiated though: If we have a simple SELECT statement such as : the process that SQL Server goes through to resolve this is : The index IX_Person_LastName_FirstName_MiddleName is navigated to find the first “Smith” For each “Smith” the middle name is checked for being a null. Two operations!, and the execution plan doesnt fully represent all the work that is being undertaken. As you can see there is only a single seek operation, the work undertaken to resolve the condition “MiddleName is not null” has been pushed into it.  This can be seen in the properties. “Seek predicate” is how the index has been navigated, and “Predicate” is the condition run over every row,  a scan inside a seek!. So the question is:  How many rows have been resolved by the seek and how many by the scan ?  How many rows did the filter remove ? Wouldn’t it be nice if this operation could be split ?  That exactly what traceflag 9130 does. Executing the query: That changes the plan rather dramatically, and should be changing how we think about the index seek itself.  The Filter operator has been added and, unsurprisingly, the condition in this is “MiddleName is not null” So it is now evident that the seek operation found 103 Smiths and 60 of those Smiths had a non-null MiddleName. This traceflag has no place on a production system,  dont even think about it

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  • Powershell: Conditionally changing objects in the pipeline

    - by axk
    I'm converting a CSV to SQL inserts and there's a null-able text column which I need to quote in case it is not NULL. I would write something like the following for the conversion: Import-Csv data.csv | foreach { "INSERT INTO TABLE_NAME (COL1,COL2) VALUES ($($_.COL1),$($_.COL2));" >> inserts.sql } But I can't figure out how to add an additional tier into the pipeline to look if COL2 is not equal to 'NULL' and to quote it in such cases. How do I achieve such behavior?

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  • Syntax of passing lambda causing hair loss (pulling out)

    - by Astara
    Right now, I'm working on refactoring a program that calls its parts by polling to a more event-driven structure. I've created sched and task classes with the sced to become a base class of the current main loop. The tasks will be created for each meter so they can be called off of that instead of polling. Each of the events main calls are a type of meter that gather info and display it. When the program is coming up, all enabled meters get 'constructed' by a main-sub. In that sub, I want to store off the "this" pointer associated with the meter, as well as the common name for the "action routine. void MeterMaker::Meter_n_Task (Meter * newmeter,) { push(newmeter); // handle non-timed draw events Task t = new Task(now() + 0.5L); t.period={0,1U}; t.work_meter = newmeter; t.work = [&newmeter](){newmeter.checkevent();};<<--attempt at lambda t.flags = T_Repeat; t.enable_task(); _xos->sched_insert(t); } A sample call to it: Meter_n_Task(new CPUMeter(_xos, "CPU ")); 've made the scheduler a base class of the main routine (that handles the loop), and I've tried serveral variations to get the task class to be a base of the meter class, but keep running into roadblocks. It's alot like "whack-a-mole" -- pound in something to fix something one place, and then a new probl pops out elsewhere. Part of the problem, is that the sched.h file that is trying to hold the Task Q, includes the Task header file. The task file Wants to refer to the most "base", Meter class. The meter class pulls in the main class of the parent as it passes a copy of the parent to the children so they can access the draw routines in the parent. Two references in the task file are for the 'this' pointer of the meter and the meter's update sub (to be called via this). void *this_data= NULL; void (*this_func)() = NULL; Note -- I didn't really want to store these in the class, as I wanted to use a lamdba in that meter&task routine above to store a routine+context to be used to call the meter's action routine. Couldn't figure out the syntax. But am running into other syntax problems trying to store the pointers...such as g++: COMPILE lsched.cc In file included from meter.h:13:0, from ltask.h:17, from lsched.h:13, from lsched.cc:13: xosview.h:30:47: error: expected class-name before ‘{’ token class XOSView : public XWin, public Scheduler { Like above where it asks for a class, where the classname "Scheduler" is. !?!? Huh? That IS a class name. I keep going in circles with things that don't make sense... Ideally I'd get the lamba to work right in the Meter_n_Task routine at the top. I wanted to only store 1 pointer in the 'Task' class that was a pointer to my lambda that would have already captured the "this" value ... but couldn't get that syntax to work at all when I tried to start it into a var in the 'Task' class. This project, FWIW, is my teething project on the new C++... (of course it's simple!.. ;-))... I've made quite a bit of progress in other areas in the code, but this lambda syntax has me stumped...its at times like thse that I appreciate the ease of this type of operation in perl. Sigh. Not sure the best way to ask for help here, as this isn't a simple question. But thought I'd try!... ;-) Too bad I can't attach files to this Q.

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