To speed up magento products imports/exports process and make database size decrease. Please run following queries of your magento database. It will truncate the unnecessary log and index tables.
TRUNCATE dataflow_batch_export;
TRUNCATE dataflow_batch_import;
TRUNCATE log_customer;
TRUNCATE log_quote;
TRUNCATE log_summary;
TRUNCATE log_summary_type;
TRUNCATE log_url;
TRUNCATE log_url_info;
TRUNCATE log_visitor;
TRUNCATE log_visitor_info;
TRUNCATE log_visitor_online;
TRUNCATE report_viewed_product_index;
TRUNCATE report_compared_product_index;
TRUNCATE report_event;
TRUNCATE index_event;
TRUNCATE catalog_compare_item;
TRUNCATE catalogindex_aggregation;
TRUNCATE catalogindex_aggregation_tag;
TRUNCATE catalogindex_aggregation_to_tag;
