Change Details

The migration plan looks like the following sequence: **I) Preparation** # update write logic so that it would write to both schemas (wb_terms and normalized one) on configuration (Task T219297 and T219295) **II) Property Terms migration (small footprint on time and size)** # write a maintenance scripts for populating the normalized tables with property terms (Task T219296) # turn on configuration for writing to both schemas for properties & run the maintenance script for properties (part of Checkpoint T219301) ``` estimated increase in disk space usage = ratio of properties/entities * current disk usage of wb_terms (incl. indexes) as of March 2019 * ratio of data size before/after normalization (accord. to test run and incl. indexes) estimated increase in disk space usage = 0.0001 * 846GB * 0.2 = ~17.5MB ``` so roughly we need extra of 18MB for property terms migration. this extra size is not expected to grow significantly before we manage to reach the point to drop the whole wb_terms. **III) Item Terms migration (big footprint on time and size)** # write a maintenance scripts for populating the normalized tables with item terms (part of Checkpoint T219122) # turn on configuration for writing to both schemas for items & run the maintenance script for items (part of Checkpoint T219123) ``` estimated increase in disk space usage = ratio of items/entities * current disk usage of wb_terms (incl. indexes) as of March 2019 * ratio of data size before/after normalization (accord. to test run and incl. indexes) estimated increase in disk space usage = 0.9999 * 846GB * 0.2 = ~170GB ```

The migration plan looks like the following sequence: **I) Preparation** # update write logic so that it would write to both schemas (wb_terms and normalized one) on configuration (Task T219297 and T219295) **II) Property Terms migration (small footprint on time and size)** # write a maintenance scripts for populating the normalized tables with property terms (Task T219296) # turn on configuration for writing to both schemas for properties & run the maintenance script for properties (part of Checkpoint T219301) ``` estimated increase in disk space usage = ratio of properties/entities * current disk usage of wb_terms (incl. indexes) as of March 2019 * ratio of data size before/after normalization (accord. to test run and incl. indexes) estimated increase in disk space usage = 0.0001 * 846GB * 0.2 = ~17.5MB ``` so roughly we need extra of 18MB for property terms migration. this extra size is not expected to grow significantly before we manage to reach the point to drop the whole wb_terms. migration time is hard to estimate, but is not expected to be long for properties. We will calculate and use that to roughly estimate item migration time. **III) Item Terms migration (big footprint on time and size)** # write a maintenance scripts for populating the normalized tables with item terms (part of Checkpoint T219122) # turn on configuration for writing to both schemas for items & run the maintenance script for items (part of Checkpoint T219123) ``` estimated increase in disk space usage = ratio of items/entities * current disk usage of wb_terms (incl. indexes) as of March 2019 * ratio of data size before/after normalization (accord. to test run and incl. indexes) estimated increase in disk space usage = 0.9999 * 846GB * 0.2 = ~170GB ``` so roughly we need extra of 170GB for item terms migration. expected increased to this number may be significant. migration time is to be estimated based on proeprty terms migration is over and measured.

The migration plan looks like the following sequence: **I) Preparation** # update write logic so that it would write to both schemas (wb_terms and normalized one) on configuration (Task T219297 and T219295) **II) Property Terms migration (small footprint on time and size)** # write a maintenance scripts for populating the normalized tables with property terms (Task T219296) # turn on configuration for writing to both schemas for properties & run the maintenance script for properties (part of Checkpoint T219301) ``` estimated increase in disk space usage = ratio of properties/entities * current disk usage of wb_terms (incl. indexes) as of March 2019 * ratio of data size before/after normalization (accord. to test run and incl. indexes) estimated increase in disk space usage = 0.0001 * 846GB * 0.2 = ~17.5MB ``` so roughly we need extra of 18MB for property terms migration. this extra size is not expected to grow significantly before we manage to reach the point to drop the whole wb_terms. migration time is hard to estimate, but is not expected to be long for properties. We will calculate and use that to roughly estimate item migration time. **III) Item Terms migration (big footprint on time and size)** # write a maintenance scripts for populating the normalized tables with item terms (part of Checkpoint T219122) # turn on configuration for writing to both schemas for items & run the maintenance script for items (part of Checkpoint T219123) ``` estimated increase in disk space usage = ratio of items/entities * current disk usage of wb_terms (incl. indexes) as of March 2019 * ratio of data size before/after normalization (accord. to test run and incl. indexes) estimated increase in disk space usage = 0.9999 * 846GB * 0.2 = ~170GB ``` so roughly we need extra of 170GB for item terms migration. expected increased to this number may be significant. migration time is to be estimated based on proeprty terms migration is over and measured.