Assessing compressed-database raw size
A computer-implemented process to assess the raw size of a compressed database involves sampling a subset of the cells of the database. The raw sizes of the sampled cells in the subset are assessed. The raw size of the database is determined based on the raw sizes of the sampled cells.
1. A computer-implemented process comprising:
sampling, by a processor coupled to a storage medium, a subset of cells of a compressed database;
assessing cell raw storage sizes of the sampled cells, wherein the assessing of the cell raw storage sizes comprises;
statistically analyzing the cell raw sizes to determine a value of a statistical parameter collectively describing the sampled cells, the sampling being random; and
determining whether additional cells should be sampled to meet a predetermined confidence level; and
assessing a database raw storage size of the compressed database based on the assessing of the cell raw storage sizes to ensure sufficient storage prior to decompressing the compressed database.
2. A process as recited in claim 1 wherein a number of the additional cells to sample is based at least in part on the value of the statistical parameter.
3. A process as recited in claim 1 wherein the determining of whether additional cells should be sampled to meet a predetermined confidence level comprises determining whether to sample the additional cells or to select the entire compressed database based at least in part on the value of the statistical parameter.
4. A process as recited in claim 1 wherein the assessing of cell raw storage sizes includes decompressing the sampled cells without decompressing other cells of the database.
5. A system comprising:
a processor;
a cell sampler to select a subset of cells of a compressed database, wherein the raw storage sizes of the subset of cells to be sampled is based, at least in part, on a variance calculated based on previously sampled cells;
a cell-size assessor to assess respective cell raw storage sizes of the subset of cells; and
a calculator to assess a database raw storage size of the compressed database based on the cell raw storage sizes of the subset of cells.
6. A system as recited in claim 5 wherein the calculator includes:
an aggregator for aggregating the cell raw storage sizes to yield an aggregate raw storage size for the cell subset; and
a scaler to scale the aggregate raw storage size to yield the database raw storage size.
7. A system as recited in claim 5 wherein the calculator includes a statistical analyzer to evaluate a statistical parameter associated with the cell raw storage sizes, the sampling being random.
8. A system as recited in claim 5 further comprising a mode selector for selecting between:
a full mode in which all cells of the database are decompressed to assess the database raw storage size; and
a statistical mode in which less than 10% of the cells of the database are decompressed to assess the database raw storage size.
9. A non-transitory computer-readable storage medium storing instructions that, when executed by a processor, cause the processor to:
sample a subset of cells of a compressed database, wherein a size of the subset of cells to be sampled is based, at least in part, on a confidence level calculated based on previously sampled cells;
assess cell raw storage sizes of the sampled cells; and
determine a database raw storage size of the compressed database based on the assessment of the cell raw storage sizes.
10. A medium as recited in claim 9 wherein the determining the database raw storage size includes:
aggregating the cell raw storage sizes to obtain an aggregate cell raw storage size; and
scaling the aggregate raw storage size to yield the database raw storage size.
11. A medium as recited in claim 9 further storing instructions that cause the processor to:
statistically analyze the cell raw storage sizes to evaluate a confidence-related parameter to obtain a parameter value, wherein the sampling is random; and
determine whether to sample additional cells based at least in part on the parameter value.
12. A medium as recited in claim 11 wherein said instructions further cause said processor to determine how many additional cells to sample based in part on the parameter value.
13. A medium as recited in claim 9 wherein the size of the subset of cells to be sampled is based, at least in part, on a variance calculated based on previously sampled cells.
14. A medium as recited in claim 9 said assessment of cell raw storage sizes yields an average cell raw storage size, said processor being caused to determine database raw storage size based on said average cell raw storage size.
15. A system as recited in claim 5 wherein the raw storage size of the subset of cells to be sampled is based, at least in part, on a confidence level calculated based on previously sampled cells.
16. A process as recited in claim 1 wherein a size of the subset of cells to be sampled is based, at least in part, on a confidence level calculated based on previously sampled cells.
17. A process as recited in claim 1 wherein the raw storage size of the subset of cells to be sampled is based, at least in part, on a variance calculated based on previously sampled cells.