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Chapter 48: Data Compression
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The result displays the following columns for each object (base table and index):object_name
schema_name
index_id
partition_number
size_with_current_compression_setting(KB)
size_with_requested_compression_setting(KB)
sample_size_with_current_compression_setting(KB)
sample_size_with_requested_compression_setting(KB)The Data Compression Wizard, as shown in Figure 48-4, uses this same system stored proce-
dure to estimate the compression. Select the type of compression to estimate, and press the
Calculate button.FIGURE 48-4
The Data Compression Wizard estimates the compression ratio and applies the selected
type of data compression.Enabling Data Compression
Data compression alters the structure of the data on the disk, so it makes sense that data
compression is enabled using a CREATE or ALTER statement.Using the UI, the only way to adjust an object’s data compression is by using the same Data
Compression Wizard used previously to estimate the compression gain.c48.indd 1105c48.indd 1105 7/31/2012 10:24:09 AM7/31/2012 10:24:09 AM
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