SQLite, a lightweight database system has become the main database engine of most of the applications such as, Android, iOS, Web browser and more. With the upcoming Smartphone era, the demand for the database has increased. The database helps to store the information in well-organized manner; users can store as well as retrieve data from the database. However, either due to mistakes or other way the data in the database file might get lost. Users realize once when they are in need of the files and gets nervous about the lost data. Actually, deletion does not mean that the data is lost forever, user can recover deleted SQLite database. It is just that, the data is removed from the corresponding location and location is marked as free. The data is deleted from the space or location only when another data overwrites the space, until then the data will be there but cannot be accessed by the user directly. If the data is overwritten, no matter how hard you try, you will not get them back.
There are some cases related to the recovery of deleted data. Let us have a discussion with those conditions.
Rules In Recovery Of Deleted Records In Applications
- If the deleted data is overwritten with zero, mainly used by web browsers such as, Chrome, Firefox 3 and Safari then, recovery is impossible.
- If the area is deleted then, no way of recovery can be made; mainly for the iPhones when deletion is done on size of data.
- If the space is left free i.e. not overwritten then, restoration of the data is possible.
Before moving with the recovery procedure, let us get an idea of structure and the location of deleted files.
Structure Of Database Page
The structure of SQLite page is as shown below.
The free space will be filled with zero initially. Apart from that, there are free blocks in the leaf pages. During the recovery process, these spaces are scanned since when a cell is deleted, it will be seen in the free blocks. How can we recover deleted SQLite database?
Recovery Procedure
The data can be recovered only if it is not overwritten with any other data i.e. the space should be free.
In-order to locate the deleted area one should scan the leaf pages, which stores the offset value of free block at offsets 2 and 3 in 2-byte. Moreover, the process involves the estimation of the variable length area that includes the header size, row ID and cell size. You will have to identify the type of the record and validate the estimated values. The validated process involves many calculations like; back-calculating the length of the cell based on the variable length and later comparing it with inputed cell’s length. The process requires many calculations to be carried out in depth. Moreover, when done, it is checked with the initial cell length. If the variable value matches with it then, recovery process can be initiated else, one should repeat the process. Actually, the process is more tedious and requires much effort.
When the recovery of database component is considered in an organization level, the stated process will be tedious. Since time and effort taken is large in the process mentioned above, people look for third party.
How Tool benefits?
There are many tools available in the market that helps you to get through the recovery of database components. SQLite database recovery tool is one such tool that helps you to recover the deleted components of the database. The hex view supported shows the deleted data in red color as well as the deleted tab shows the data that are deleted. Once when export the files all the data deleted will also be exported. The tool flawlessly recovers all the deleted components of the SQLite database. Anyone can use this tool since it does not require much technical knowledge.
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