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  • Wireless internet is connected to an open network but has no internet

    - by Joshua Reeder
    I just installed Ubuntu on my laptop yesterday and it connected to the wireless fine. Then I took it to school, put it on their wired connection, downloaded some stuff, and now the wireless doesn't work. At first it would detect networks, but not connect. I restarted it and now it can connect, but it acts like it doesn't have internet in the browser. Wired connection still works fine on it. I know it isn't the network because my ipad is working on the wireless connection fine. I found another solution on here switching the security settings for the wireless, but this is the apartment's wireless so they have it open, and I won't be able to mess with it at all. Here is lspci output: 00:00.0 Host bridge: Intel Corporation Core Processor DMI (rev 11) 00:03.0 PCI bridge: Intel Corporation Core Processor PCI Express Root Port 1 (rev 11) 00:08.0 System peripheral: Intel Corporation Core Processor System Management Registers (rev 11) 00:08.1 System peripheral: Intel Corporation Core Processor Semaphore and Scratchpad Registers (rev 11) 00:08.2 System peripheral: Intel Corporation Core Processor System Control and Status Registers (rev 11) 00:08.3 System peripheral: Intel Corporation Core Processor Miscellaneous Registers (rev 11) 00:10.0 System peripheral: Intel Corporation Core Processor QPI Link (rev 11) 00:10.1 System peripheral: Intel Corporation Core Processor QPI Routing and Protocol Registers (rev 11) 00:16.0 Communication controller: Intel Corporation 5 Series/3400 Series Chipset HECI Controller (rev 06) 00:1a.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 05) 00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev 05) 00:1c.0 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 (rev 05) 00:1c.1 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 2 (rev 05) 00:1c.2 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 3 (rev 05) 00:1c.3 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 4 (rev 05) 00:1c.4 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 5 (rev 05) 00:1d.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 05) 00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev a5) 00:1f.0 ISA bridge: Intel Corporation Mobile 5 Series Chipset LPC Interface Controller (rev 05) 00:1f.2 SATA controller: Intel Corporation 5 Series/3400 Series Chipset 4 port SATA AHCI Controller (rev 05) 00:1f.3 SMBus: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller (rev 05) 01:00.0 VGA compatible controller: NVIDIA Corporation GT218 [GeForce 310M] (rev a2) 01:00.1 Audio device: NVIDIA Corporation High Definition Audio Controller (rev a1) 02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller (rev 05) 07:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8191SEvB Wireless LAN Controller (rev 10) 16:00.0 System peripheral: JMicron Technology Corp. SD/MMC Host Controller (rev 20) 16:00.2 SD Host controller: JMicron Technology Corp. Standard SD Host Controller (rev 20) 16:00.3 System peripheral: JMicron Technology Corp. MS Host Controller (rev 20) 16:00.4 System peripheral: JMicron Technology Corp. xD Host Controller (rev 20) ff:00.0 Host bridge: Intel Corporation Core Processor QuickPath Architecture Generic Non-Core Registers (rev 04) ff:00.1 Host bridge: Intel Corporation Core Processor QuickPath Architecture System Address Decoder (rev 04) ff:02.0 Host bridge: Intel Corporation Core Processor QPI Link 0 (rev 04) ff:02.1 Host bridge: Intel Corporation Core Processor QPI Physical 0 (rev 04) ff:03.0 Host bridge: Intel Corporation Core Processor Integrated Memory Controller (rev 04) ff:03.1 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Target Address Decoder (rev 04) ff:03.4 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Test Registers (rev 04) ff:04.0 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Channel 0 Control Registers (rev 04) ff:04.1 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Channel 0 Address Registers (rev 04) ff:04.2 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Channel 0 Rank Registers (rev 04) ff:04.3 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Channel 0 Thermal Control Registers (rev 04) ff:05.0 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Channel 1 Control Registers (rev 04) ff:05.1 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Channel 1 Address Registers (rev 04) ff:05.2 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Channel 1 Rank Registers (rev 04) ff:05.3 Host bridge: Intel Corporation Core Processor Integrated Memory Controller Channel 1 Thermal Control Registers (rev 04) Update: I re-installed Ubuntu 12.04 (I assumed I messed something up while toying with it) but it did not solve the problem. Eventually, I got it to work with my school's wireless internet (the default network settings were wrong), but the internet still doesn't work on my apartment's wifi (it has no security on it).

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  • SQL SERVER – ASYNC_IO_COMPLETION – Wait Type – Day 11 of 28

    - by pinaldave
    For any good system three things are vital: CPU, Memory and IO (disk). Among these three, IO is the most crucial factor of SQL Server. Looking at real-world cases, I do not see IT people upgrading CPU and Memory frequently. However, the disk is often upgraded for either improving the space, speed or throughput. Today we will look at another IO-related wait type. From Book On-Line: Occurs when a task is waiting for I/Os to finish. ASYNC_IO_COMPLETION Explanation: Any tasks are waiting for I/O to finish. If by any means your application that’s connected to SQL Server is processing the data very slowly, this type of wait can occur. Several long-running database operations like BACKUP, CREATE DATABASE, ALTER DATABASE or other operations can also create this wait type. Reducing ASYNC_IO_COMPLETION wait: When it is an issue related to IO, one should check for the following things associated to IO subsystem: Look at the programming and see if there is any application code which processes the data slowly (like inefficient loop, etc.). Note that it should be re-written to avoid this  wait type. Proper placing of the files is very important. We should check the file system for proper placement of the files – LDF and MDF on separate drive, TempDB on another separate drive, hot spot tables on separate filegroup (and on separate disk), etc. Check the File Statistics and see if there is a higher IO Read and IO Write Stall SQL SERVER – Get File Statistics Using fn_virtualfilestats. Check event log and error log for any errors or warnings related to IO. If you are using SAN (Storage Area Network), check the throughput of the SAN system as well as configuration of the HBA Queue Depth. In one of my recent projects, the SAN was performing really badly and so the SAN administrator did not accept it. After some investigations, he agreed to change the HBA Queue Depth on the development setup (test environment). As soon as we changed the HBA Queue Depth to quite a higher value, there was a sudden big improvement in the performance. It is very likely to happen that there are no proper indexes on the system and yet there are lots of table scans and heap scans. Creating proper index can reduce the IO bandwidth considerably. If SQL Server can use appropriate cover index instead of clustered index, it can effectively reduce lots of CPU, Memory and IO (considering cover index has lesser columns than cluster table and all other; it depends upon the situation). You can refer to the following two articles I wrote that talk about how to optimize indexes: Create Missing Indexes Drop Unused Indexes Checking Memory Related Perfmon Counters SQLServer: Memory Manager\Memory Grants Pending (Consistent higher value than 0-2) SQLServer: Memory Manager\Memory Grants Outstanding (Consistent higher value, Benchmark) SQLServer: Buffer Manager\Buffer Hit Cache Ratio (Higher is better, greater than 90% for usually smooth running system) SQLServer: Buffer Manager\Page Life Expectancy (Consistent lower value than 300 seconds) Memory: Available Mbytes (Information only) Memory: Page Faults/sec (Benchmark only) Memory: Pages/sec (Benchmark only) Checking Disk Related Perfmon Counters Average Disk sec/Read (Consistent higher value than 4-8 millisecond is not good) Average Disk sec/Write (Consistent higher value than 4-8 millisecond is not good) Average Disk Read/Write Queue Length (Consistent higher value than benchmark is not good) Read all the post in the Wait Types and Queue series. Note: The information presented here is from my experience and there is no way that I claim it to be accurate. I suggest reading Book OnLine for further clarification. All the discussions of Wait Stats in this blog are generic and vary from system to system. It is recommended that you test this on a development server before implementing it to a production server. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Stats, SQL Wait Types, T SQL, Technology

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  • SQL SERVER – IO_COMPLETION – Wait Type – Day 10 of 28

    - by pinaldave
    For any good system three things are vital: CPU, Memory and IO (disk). Among these three, IO is the most crucial factor of SQL Server. Looking at real-world cases, I do not see IT people upgrading CPU and Memory frequently. However, the disk is often upgraded for either improving the space, speed or throughput. Today we will look at an IO-related wait types. From Book On-Line: Occurs while waiting for I/O operations to complete. This wait type generally represents non-data page I/Os. Data page I/O completion waits appear as PAGEIOLATCH_* waits. IO_COMPLETION Explanation: Any tasks are waiting for I/O to finish. This is a good indication that IO needs to be looked over here. Reducing IO_COMPLETION wait: When it is an issue concerning the IO, one should look at the following things related to IO subsystem: Proper placing of the files is very important. We should check the file system for proper placement of files – LDF and MDF on a separate drive, TempDB on another separate drive, hot spot tables on separate filegroup (and on separate disk),etc. Check the File Statistics and see if there is higher IO Read and IO Write Stall SQL SERVER – Get File Statistics Using fn_virtualfilestats. Check event log and error log for any errors or warnings related to IO. If you are using SAN (Storage Area Network), check the throughput of the SAN system as well as the configuration of the HBA Queue Depth. In one of my recent projects, the SAN was performing really badly so the SAN administrator did not accept it. After some investigations, he agreed to change the HBA Queue Depth on development (test environment) set up and as soon as we changed the HBA Queue Depth to quite a higher value, there was a sudden big improvement in the performance. It is very possible that there are no proper indexes in the system and there are lots of table scans and heap scans. Creating proper index can reduce the IO bandwidth considerably. If SQL Server can use appropriate cover index instead of clustered index, it can effectively reduce lots of CPU, Memory and IO (considering cover index has lesser columns than cluster table and all other; it depends upon the situation). You can refer to the two articles that I wrote; they are about how to optimize indexes: Create Missing Indexes Drop Unused Indexes Checking Memory Related Perfmon Counters SQLServer: Memory Manager\Memory Grants Pending (Consistent higher value than 0-2) SQLServer: Memory Manager\Memory Grants Outstanding (Consistent higher value, Benchmark) SQLServer: Buffer Manager\Buffer Hit Cache Ratio (Higher is better, greater than 90% for usually smooth running system) SQLServer: Buffer Manager\Page Life Expectancy (Consistent lower value than 300 seconds) Memory: Available Mbytes (Information only) Memory: Page Faults/sec (Benchmark only) Memory: Pages/sec (Benchmark only) Checking Disk Related Perfmon Counters Average Disk sec/Read (Consistent higher value than 4-8 millisecond is not good) Average Disk sec/Write (Consistent higher value than 4-8 millisecond is not good) Average Disk Read/Write Queue Length (Consistent higher value than benchmark is not good) Note: The information presented here is from my experience and there is no way that I claim it to be accurate. I suggest reading Book OnLine for further clarification. All the discussions of Wait Stats in this blog are generic and vary from system to system. It is recommended that you test this on a development server before implementing it to a production server. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Pinal Dave, PostADay, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Server, SQL Tips and Tricks, SQL Wait Types, SQL White Papers, T SQL, Technology

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  • How can I install oracle-java7 from webupd8 ppa?

    - by Ahmed Zain El Dein
    I installed ppa:webupd8team/java and I get the following error Output from: sudo apt-get install oracle-java7-installer Reading package lists... Done Building dependency tree Reading state information... Done Suggested packages: binfmt-support visualvm ttf-baekmuk ttf-unfonts ttf-unfonts-core ttf-kochi-gothic ttf-sazanami-gothic ttf-kochi-mincho ttf-sazanami-mincho ttf-arphic-uming The following packages will be upgraded: oracle-java7-installer 1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 1 not fully installed or removed. Need to get 0 B/16.0 kB of archives. After this operation, 64.5 kB of additional disk space will be used. Could not exec dpkg! E: Sub-process /usr/bin/dpkg returned an error code (100) i did afterwords those line of code trying to resolve the issue becuase it is not existed actually in the /usr/bin/dpkg there is no dpkg mkdir /tmp/dpkg cd /tmp/dpkg wget http://archive.ubuntu.com/ubuntu/pool/main/d/dpkg/dpkg_1.15.5.6ubuntu4_i386.deb ar x dpkg*.deb data.tar.gz tar xfvz data.tar.gz ./usr/bin/dpkg sudo cp ./usr/bin/dpkg /usr/bin/ sudo apt-get update sudo apt-get install --reinstall dpkg then i get this $ sudo apt-get install --reinstall dpkg Reading package lists... Done Building dependency tree Reading state information... Done 0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 6 not upgraded. 1 not fully installed or removed. Need to get 0 B/1,814 kB of archives. After this operation, 0 B of additional disk space will be used. dpkg: warning: 'dpkg-deb' not found on PATH. dpkg: 1 expected program(s) not found on PATH. NB: root's PATH should usually contain /usr/local/sbin, /usr/sbin and /sbin. E: Sub-process /usr/bin/dpkg returned an error code (2) How can I fix this?

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  • How can I design my classes to include calendar events stored in a database?

    - by Gianluca78
    I'm developing a web calendar in php (using Symfony2) inspired by iCal for a project of mine. At this moment, I have two classes: a class "Calendar" and a class "CalendarCell". Here you are the two classes properties and method declarations. class Calendar { private $month; private $monthName; private $year; private $calendarCellList = array(); private $translator; public function __construct($month, $year, $translator) {} public function getCalendarCellList() {} public function getMonth() {} public function getMonthName() {} public function getNextMonth() {} public function getNextYear() {} public function getPreviousMonth() {} public function getPreviousYear() {} public function getYear() {} private function calculateDaysPreviousMonth() {} private function calculateNumericDayOfTheFirstDayOfTheWeek() {} private function isCurrentDay(\DateTime $dateTime) {} private function isDifferentMonth(\DateTime $dateTime) {} } class CalendarCell { private $day; private $month; private $dayNameAbbreviation; private $numericDayOfTheWeek; private $isCurrentDay; private $isDifferentMonth; private $translator; public function __construct(array $parameters) {} public function getDay() {} public function getMonth() {} public function getDayNameAbbreviation() {} public function isCurrentDay() {} public function isDifferentMonth() {} } Each calendar day can includes many calendar events (such as appointments or schedules) stored in a database. My question is: which is the best way to manage these calendar events in my classes? I think to add a eventList property in CalendarCell and populate it with an array of CalendarEvent objects fetched by the database. This kind of solution doesn't allow other coders to reuse the classes without db (because I should inject at least a repository services also) just to create and visualize a calendar... so maybe it could be better to extend CalendarCell (for instance in CalendarCellEvent) and add the database features? I feel like I'm missing some crucial design pattern! Any suggestion will be very appreciated!

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  • Using Queries with Coherence Read-Through Caches

    - by jpurdy
    Applications that rely on partial caches of databases, and use read-through to maintain those caches, have some trade-offs if queries are required. Coherence does not support push-down queries, so queries will apply only to data that currently exists in the cache. This is technically consistent with "read committed" semantics, but the potential absence of data may make the results so unintuitive as to be useless for most use cases (depending on how much of the database is held in cache). Alternatively, the application itself may manually "push down" queries to the database, either retrieving results equivalent to querying the cache directly, or may query the database for a key set and read the values from the cache (relying on read-through to handle any missing values). Obviously, if the result set is too large, reading through the cache may cause significant thrashing. It's also worth pointing out that if the cache is asynchronously synchronized with the database (perhaps via database change listener), that an application may commit a transaction to the database, then generate a key set from the database via a query, then read cache entries through the cache, possibly resulting in a race condition where the application sees older data than it had previously committed. In theory this is not problematic but in practice it is very unintuitive. For this reason it often makes sense to invalidate the cache when updating the database, forcing the next read-through to update the cache.

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  • How can I design my classes for a calendar based on database events?

    - by Gianluca78
    I'm developing a web calendar in php (using Symfony2) inspired by iCal for a project of mine. At this moment, I have two classes: a class "Calendar" and a class "CalendarCell". Here you are the two classes properties and method declarations. class Calendar { private $month; private $monthName; private $year; private $calendarCellList = array(); private $translator; public function __construct($month, $year, $translator) {} public function getCalendarCells() {} public function getMonth() {} public function getMonthName() {} public function getNextMonth() {} public function getNextYear() {} public function getPreviousMonth() {} public function getPreviousYear() {} public function getYear() {} private function calculateDaysPreviousMonth() {} private function calculateNumericDayOfTheFirstDayOfTheWeek() {} private function isCurrentDay(\DateTime $dateTime) {} private function isDifferentMonth(\DateTime $dateTime) {} } class CalendarCell { private $day; private $month; private $dayNameAbbreviation; private $numericDayOfTheWeek; private $isCurrentDay; private $isDifferentMonth; private $translator; public function __construct(array $parameters) {} public function getDay() {} public function getMonth() {} public function getDayNameAbbreviation() {} public function isCurrentDay() {} public function isDifferentMonth() {} } Each calendar day can includes many events stored in a database. My question is: which is the best way to manage these events in my classes? I think to add a eventList property in CalendarCell and populate it with an array of CalendarEvent objects fetched by the database. This kind of solution doesn't allow other coders to reuse the classes without db (because I should inject at least a repository services also) just to create and visualize a calendar... so maybe it could be better to extend CalendarCell (for instance in CalendarCellEvent) and add the database features? I feel like I'm missing some crucial design pattern! Any suggestion will be very appreciated!

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  • PHP Code (modules) included via MySQL database, good idea?

    - by ionFish
    The main script includes "modules" which add functionality to it. Each module is set up like this: <?php //data collection stuff //(...) approx 80 lines of code //end data collection $var1 = 'some data'; $var2 = 'more data'; $var3 = 'other data'; ?> Each module has the same exact variables, just the data collection is different. I was wondering if it's a reasonable idea to store the module data in MySQL like this: [database] |_modules |_name |_function (the raw PHP data from above) |_description |_author |_update-url |_version |_enabled ...and then include the PHP-data from the database and execute it? Something like, a tab-navigation system at the top of the page for each module name, then inside each of those tabs the page content would function by parsing the database-stored code of the module from the function section. The purpose would be to save code space (fewer lines), allow for easy updates, and include/exclude modules based on the enabled option. This is how many other web-apps work, some of my own too. But never had I thought about this so deeply. Are there any drawbacks or security risks to this?

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  • "Create table if not exists" - how to check the schema, too?

    - by Joonas Pulakka
    Is there a (more or less) standard way to check not only whether a table named mytable exists, but also whether its schema is similar to what it should be? I'm experimenting with H2 database, and CREATE TABLE IF NOT EXISTS mytable (....) statements apparently only check for the table´s name. I would expect to get an exception if there's a table with the given name, but different schema.

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  • Pay online service

    - by Samuel
    Hellow, I have a database where you can select articles etc, users have an account, it's all in mysql and php (i guess you don't need that code). What i was wondering was how to write a script that allows users to pay online for the articles they selected? It doesn't need to be any code, just ideas / hints / tips / ... (that are doable in PHP or something similar) Thanks in advance!! -Samuel

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  • SQLCODE -1390 connecting to DB2 64 bit client from 32 bit app

    - by Oliver Abraham
    Hi there, I've got a 32 bit application that connects normally to a DB2 database. (written in C) When I run it on a machine with a DB2 64 bit client, I get a SQLCODE -1390 from connect. (Win7 64 Bit, DB2 V9.7 client 64 bit) Connecting from the command line works (db2 connect to ...) With a 32 Bit DB2 client on the same Win7 64 Bit machine, the connect also works. Does anyone has an idea how to fix it ? Best regards Oliver

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  • Star Schema vs Snowflake Schema performance

    - by Megawolt
    Hi... I'm begin to developing a scial sharing website so I'm curious about database design Schema... So in Data-Mining Star-Schema is the best one but how about a social sharing website... And as a nature of the SS websites there will be (i hope :)) many users in same time... Which better for performance for overdose using...

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  • How do I drop SQL Databases? sp_delete_database_backuphistory woes

    - by rlb.usa
    I want to delete some SQL Databases on my server, but I'm having problems. My login has the roles: public dbcreator serveradmin When I right click the database and hit Delete, it says that Delete backup history failed for server 'MYSERVER' (Microsoft.SqlServer.Smo) Additional Information: The EXECUTE permission was denied on the object 'sp_delete_database_backuphistory' How do I delete these databases?

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  • Many-to-many relations in RDBMS databases

    - by Industrial
    What is the best way of handling many-to-many relations in a RDBMS database like mySQL? Have tried using a pivot table to keep track of the relationships, but it leads to either one of the following: Normalization gets left behind Columns that is empty or null What approach have you taken in order to support many-to-many relationships?

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  • Access Error when running windows program

    - by JPJedi
    I have a windows form application that uses microsoft access for the database on the backend. When I run that application I get an error that says access is not installed on the computer. I thought that if I included the reference that it will be included with what I release so the user would not have to have access installed. How do I include the Access Runtime to be distributed/installed when my application is installed?

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  • What’s the strategy to recover data during DAO unit test?

    - by Michael Lu
    When I test DAO module in JUnit, an obvious problem is: how to recover testing data in database? For instance, a record should be deleted in both test methods testA() and testB(), that means precondition of both test methods need an existing record to be deleted. Then my strategy is inserting the record in setUp() method to recover data. What’s your better solution? Or your practical idea in such case? Thanks

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  • Using Amazon's EBS for MySQL hot backup

    - by flybywire
    What are your experiences using Amazons EBS snapshot features for MySql hot backups. I have a database running a batch processing job in ec2. I backup with EBS snapshot. So far the backups looks consistent. But I am afraid they "will stop being consistent as soon as I stop checking" (Uncertainty principle). What are your experiences with backuping relational databases (and mysql in particular) with ebs snapshot?

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  • Class Map Generator for Fluent NHibernate

    - by Farzad
    Is there a Class Map generator for Fluent NHibernate? I need something like db2hbm but I want it to generate Fluent Class Maps instead of xml mappings. I am aware of AutoMapping for Fluent but that is not what I want. I want to be able to generate Class Map files from tables in database and push them to my src repository.

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  • SQL using with clause not working

    - by user1290467
    My question is why this query does not work? Cursor c = db.rawQuery("SELECT * FROM tbl_staff WHERE PMajor = '%" + spin.getSelectedItem().toString() + "%'", null); Cursor c: it is a cursor for handling my query tbl_staff: my table that consist of PName,PMajor,PCert spin: is spinner that has values which I need for my database query. When I use: if (c.moveToNext()) else (log.d("error query","couldn't do the query!");) It goes to else statement and moveToNext() doesn't work.

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  • Creating thousands of records in Rails

    - by willCosgrove
    Let me set the stage: My application deals with gift cards. When we create cards they have to have a unique string that the user can use to redeem it with. So when someone orders our gift cards, like a retailer, we need to make a lot of new card objects and store them in the DB. With that in mind, I'm trying to see how quickly I can have my application generate 100,000 Cards. Database expert, I am not, so I need someone to explain this little phenomena: When I create 1000 Cards, it takes 5 seconds. When I create 100,000 cards it should take 500 seconds right? Now I know what you're wanting to see, the card creation method I'm using, because the first assumption would be that it's getting slower because it's checking the uniqueness of a bunch of cards, more as it goes along. But I can show you my rake task desc "Creates cards for a retailer" task :order_cards, [:number_of_cards, :value, :retailer_name] => :environment do |t, args| t = Time.now puts "Searching for retailer" @retailer = Retailer.find_by_name(args[:retailer_name]) puts "Retailer found" puts "Generating codes" value = args[:value].to_i number_of_cards = args[:number_of_cards].to_i codes = [] top_off_codes(codes, number_of_cards) while codes != codes.uniq codes.uniq! top_off_codes(codes, number_of_cards) end stored_codes = Card.all.collect do |c| c.code end while codes != (codes - stored_codes) codes -= stored_codes top_off_codes(codes, number_of_cards) end puts "Codes are unique and generated" puts "Creating bundle" @bundle = @retailer.bundles.create!(:value => value) puts "Bundle created" puts "Creating cards" @bundle.transaction do codes.each do |code| @bundle.cards.create!(:code => code) end end puts "Cards generated in #{Time.now - t}s" end def top_off_codes(codes, intended_number) (intended_number - codes.size).times do codes << ReadableRandom.get(CODE_LENGTH) end end I'm using a gem called readable_random for the unique code. So if you read through all of that code, you'll see that it does all of it's uniqueness testing before it ever starts creating cards. It also writes status updates to the screen while it's running, and it always sits for a while at creating. Meanwhile it flies through the uniqueness tests. So my question to the stackoverflow community is: Why is my database slowing down as I add more cards? Why is this not a linear function in regards to time per card? I'm sure the answer is simple and I'm just a moron who knows nothing about data storage. And if anyone has any suggestions, how would you optimize this method, and how fast do you think you could get it to create 100,000 cards? (When I plotted out my times on a graph and did a quick curve fit to get my line formula, I calculated how long it would take to create 100,000 cards with my current code and it says 5.5 hours. That maybe completely wrong, I'm not sure. But if it stays on the line I curve fitted, it would be right around there.)

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