What is difference between database Mirroring and Replication?
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The terms replication and remote mirroring are frequently used interchangeably because their meanings are very similar. Replication is the process of duplicating primary data volumes over an IP connection to a storage subsystem at an alternate location. This redundant copy can then be used by business applications if access to the primary data is interrupted. The source and target of a replication are usually separated by a significant distance to safeguard data from disasters that effect a specific geographic location, such as a region-wide power outage.\n\nReplication techniques have two principle modes: asynchronous and synchronous. With asynchronous replication, the primary and secondary data volumes are no more than a few milliseconds out of sync, so the replication is nearly real-time. With synchronous replication, the primary and secondary copies are always identical, so it provides a true real-time duplication. (See Replication.)\n\nLike replication, remote mirroring uses redundancy to guarantee data availability. A remote mirrored data volume consists of two identical copies of the data connected by Fibre Channel. Both sides of a mirror process read and write I/Os to ensure each copy is a real-time duplicate of the other. The mirror copies are housed in separate data centers, connected over a local- or metro-area network (LAN or MAN). If a disaster interrupts access to one side of a mirror, the surviving copy will continue to service application I/O requests and therefore minimize the disruption to business users. \n\n...verbatim from veritas.com website
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both of the databases have the ability to return consistent (correct) \nresults.  Only oracle can do so in a mixed workload environment (mixed \nupdates and reads) in a highly concurrent fashion.  In Oracle we employ \nmulti-versioning and read consistency.  The others use shared read locks (which \nwill lead to deadlocks and blocking).  We never block on a read -- they \nfrequently block on a read.  So, another feature with a check mark that is \nvirtually meaningless
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Access is a file based database and Microsoft SQL Server a client server database.\nAccess utilises a File Server design while SQL Server employs a Client/Server approach. This is a fundamentally different architecture which has many, many implications.
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It depends on the configuration of the server.  Maybe they have a database that maintains a fixed size by removing older entries.  Still though, just being "a server" won't mean that the computer will or won't remove data, it depends entirely one what it does and how the owners want it to run.
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A longer term solution would be to use database aliases / synonyms so that the schema and table names could remain the same across environments.
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I use mirrors only when I need integrity and only have 2 drives to work with.  In the case of having three or more drives, and a Raid 5 controller, you (a) get more space and (b) get more speed and STILL have fault tolerance using Raid 5.\n\nNote, in either case, the "space used per disk" in a mirror or Raid 5 is equal to the SMALLEST disk drive, so if you have 3 LARGE drives and 2 SMALL ones, I might go with the Raid 5 on the three large disks and mirror on the two smaller.\n\nFor example 3 - 200GB drives and 2 - 100GB drives\n\nRaid 5 using all 5 disks = 5 * 100GB (smallest drive) - 100GB(smallest drive) = 400GB\n\nRaid 5 on three and Mirror on two = (3 * 200GB - 200GB) + (100 GB) = 500GB
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Benefits/Problems\n\nAccess:\n\n is much cheaper\n is not very scalable mostly for personal use for very few users\n is not very roboust\n works only on windows OS\n\nOrcale\n is scalable/reliable\nVery costly\nworks with all operating systems\n\nWhat DB can handle what?\n\nAccess can atmost handle 5-10 concurrent users\n\nOracle can handle many many more depending on the version you purchase\n\nWhich is faster?\n\nundoubltedly oracle\n\nSecurity/Reliablilty?\n\nundoubltedly oracle
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Well, you haven't really talked about what you want to do with them, but I'm assuming one is going to be read only.\n\nYou could set up one as a publisher and the other as a subscriber and allow the two systems to replicate periodically based on time triggers.
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sql server is an application that runs on a server. It provides to a developer and easy way to implement database functions. Yes, it is faster than doing it with other methods.
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The biggest differences are going to be the size of you database and your security.  Businesses are going to need dedicated storage area and firewalls and/or proxy servers.  Home networks can do most of this through software instead of hardware.
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The previous answer is correct - however, unless we're talking about a high volume of data, I prefer to use an MS Access backend database instead - I think it's easier to maintain.\n\nHowever, as the previous respondent said, the key is finding an ISP whose platform supports your platform.
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Copying data byte by byte without looking at the bigger picture like the file or application you are actually trying to replicate to another site. This ensures system indifference, some level of security and sometimes it is the only way to copy across different storage networks. Fairly useful technology.
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RAID 1\nA RAID 1 creates an exact copy (or mirror) of a set of data on two or more disks. This is useful when read performance is more important than minimizing the storage capacity used for redundancy. The array can only be as big as the smallest member disk, however. A classic RAID 1 mirrored pair contains two disks, which increases reliability by a factor of two over a single disk, but it is possible to have many more than two copies. Since each member can be addressed independently if the other fails, reliability is a linear multiple of the number of members. To truly get the full redundancy benefits of RAID 1, independent disk controllers are recommended, one for each disk. Some refer to this practice as splitting or duplexing.\n\nWhen reading, both disks can be accessed independently. Like RAID 0 the average seek time is reduced by half when randomly reading but because each disk has the exact same data the requested sectors can always be split evenly between the disks and the seek time remains low. The transfer rate would also be doubled. For three disks the seek time would be a third and the transfer rate would be tripled. The only limit is how many disks can be connected to the controller and its maximum transfer speed. Many older IDE RAID 1 cards read from one disk in the pair, so their read performance is that of a single disk. Some older RAID 1 implementations would also read both disks simultaneously and compare the data to catch errors. The error detection and correction on modern disks makes this less useful in environments requiring normal commercial availability. When writing, the array performs like a single disk as all mirrors must be written with the data.\n\nRAID 1 has many administrative advantages. For instance, in some 365*24 environments, it is possible to "Split the Mirror": declare one disk as inactive, do a backup of that disk, and then "rebuild" the mirror. This requires that the application support recovery from the image of data on the disk at the point of the mirror split. This procedure is less critical in the presence of the "snapshot" feature of some filesystems, in which some space is reserved for changes, presenting a static point-in-time view of the filesystem. Alternatively, a set of disks can be kept in much the same way as traditional backup tapes are.\n\nAlso, one common practice is to create an extra mirror of a volume (also known as a Business Continuance Volume or BCV) which is meant to be split from the source RAID set and used independently. In some implementations, these extra mirrors can be split and then incrementally re-established, instead of requiring a complete RAID set rebuild.\n\n Traditional\n   RAID 1\nA1        A1\nA2        A2\nA3        A3\nA4        A4\n\nNote: A1, A2, et cetera each represent one data block; each column represents one disk.\n\n\nRAID 2\nA RAID 2 stripes data at the bit (rather than block) level, and uses a Hamming code for error correction. The disks are synchronized by the controller to run in perfect tandem. This is the only original level of RAID that is not currently used. Extremely high data transfer rates are possible.\n\n\nRAID 3\nA RAID 3 uses byte-level striping with a dedicated parity disk. RAID 3 is very rare in practice. One of the side effects of RAID 3 is that it generally cannot service multiple requests simultaneously. This comes about because any single block of data will by definition be spread across all members of the set and will reside in the same location, so any I/O operation requires activity on every disk.\n\nIn our example below, a request for block "A" consisting of bytes A1-A9, would require all three data disks to seek to the beginning(A1) and reply with their contents. A simultaneous request for block B would have to wait.\n\n  Traditional\n    RAID 3\nA1  A2  A3  Ap(1-3)\nA4  A5  A6  Ap(4-6)\nA7  A8  A9  Ap(7-9)\nB1  B2  B3  Bp(1-3)\n\nNote: A1, B1, etcetera each represent one
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I understand you want to implement something like Peer to Peer file sharing but, instead backups.\nThis is not efficient because first of all backups are large and they cannot be easily transferred, also there would be huge netwrok traffic.\nThey must kept safe and secure.\nThe transmission is not safe, as your application may open a port on each computer.\nYou would have firewall issue.\nThere are FTP services for such a purpose.\nBut I can give you a better Idea.\nTo setup a central Virtual Backup Server.\nThis is a virtual Private Netwrok that has a storage and allocates storage for each user, The server should use FTP, or TCP (HTTP like file manager), and the server should kept safe.\nI would suggest use Hosting from data centres, Like Brinkster.com.\nthe setup is easy and you may not need any other applications to build.\nHowever you should be aware of your bandwitdh limit.\n;) good Luck\nMrB
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Web pages generally fit in Enterprise Applications category.In this model the request is served by one server or multiple servers located at different geographical locations.And to store data a separate database server is used.
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Normally a database admin is going to do just that, administer a database. That may be Oracle, SQL Server or the like. They may design databases, tune queries, perform backup and recovery operations, and help spec things out. A storage admin is going to deal more with actual drive setups. Raid mirrored arrays, making sure drive space is available for the network, space for email on exchange and the like. A database administrator shouldnt have to worry about drive space and a storage admin shouldnt be concerned with the technical aspects of what database is used. The two roles may crossover in small organizations, but as you have them listed, they are two very different roles.
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Here is a free program for you:\nhttp://www.httrack.com/\n\nIt runs on Windows and Linux.  Works great.\n\nThis is from the web site:\n"It allows you to download a World Wide Web site from the Internet to a local directory, building recursively all directories, getting HTML, images, and other files from the server to your computer. HTTrack arranges the original site's relative link-structure. Simply open a page of the "mirrored" website in your browser, and you can browse the site from link to link, as if you were viewing it online. HTTrack can also update an existing mirrored site, and resume interrupted downloads. HTTrack is fully configurable, and has an integrated help system."