The csmerge Command Manual Page

NAME
SYNOPSIS
DESCRIPTION
OPTIONS
EXIT STATUS
ENVIRONMENT
FILES
EXAMPLES
SEE ALSO
AUTHOR

NAME

csmerge - merge multiple CScout database shards

SYNOPSIS

csmerge [-k] [-l file] [-T dir] nfiles merged.db

DESCRIPTION

csmerge merges a set of CScout SQLite database shards into a single database.

The program expects as input nfiles SQLite database files. These are merged into the specified merged.db output database file. The resulting file preserves the semantics of CScout processing, including primary key assignments, foreign key references, and token splits. The number of input databases must be a power of two, e.g. 2, 4, 16, or 64. Each input database is named using a zero-padded sequence, starting with file-0000.db. The databases are typically produced by CScout processing a larger CScout file split into multiple parts with cssplit(1). Large temporary files are created during the merge and removed when finished, unless instructed otherwise. During the processing the commands sqlite3(1) and cscout(1) are invoked to handle the merging.

OPTIONS

-k

Preserve temporary files created during execution.

-l file

Write logs to the specified file. The default log file is dbmerge.log.

-T dir

Use dir as the temporary directory. Defaults to the value of TMPDIR if set, otherwise /tmp.

EXIT STATUS

Returns 0 on success, nonzero on errors.

ENVIRONMENT

TMPDIR

Temporary directory if -T is not provided. The temporary directory must have enough space to store the resulting database, which will be about 30% larger than the total size of the combined database files.

FILES

dbmerge.log

Default log output.

EXAMPLES

Below is a complete example of splitting the processing of several Linux kernel configurations into 64 chunks and then merging the results.

# Create and use a space for the split data.
mkdir parallel
cd parallel

# Split configurations into multiple files.
cssplit -s 64 ../linux-*.cs

# Run CScout on all split files in parallel.
for f in file-*.cs ; do
  cscout -s sqlite $f | sqlite3 $f.db &
done

# Wait for the CScout jobs to finish.
while wait -n; do :; done


# Merge the results into a single database.
csmerge 64 ../merged.db