To create a report that shows the company's year-over-year Q2 2020 sales, the analyst should compare the sales data from Q2 2020 and Q2 2019. Year-over-year (YoY) analysis is a method of comparing the performance of a business or a financial instrument over the same period in different years. It helps to identify trends, growth patterns, and seasonal fluctuations. Q2 refers to the second quarter of a year, which is usually from April to June. Therefore, the correct answer is C. References: YoY - Year over Year Analysis - Definition, Explanation & Examples, What is an Annual Sales Report: Definition, metrics, and tips - Snov.io

Comprehensive and Detailed In-Depth Explanation:
Improving the performance of large dimension tables in a database is crucial for efficient data retrieval and processing.
* Partitioning: This technique involves dividing a large table into smaller, more manageable pieces called partitions. Each partition can be accessed and maintained separately, which enhances query performance and simplifies data management. Partitioning allows the database to read only the relevant partitions during a query, reducing the amount of data processed and speeding up response times.
* Sampling: This involves analyzing a subset of data rather than the entire dataset. While useful for statistical analysis, it doesn't improve the performance of queries on the full dataset.
* Windowing: This refers to functions that perform calculations across a set of table rows related to the current row, such as moving averages. It's useful for analytical purposes but doesn't inherently improve table performance.
* Sorting: Organizing data in a specific order can aid in readability and certain query operations but doesn't significantly impact performance on large tables unless combined with indexing.
Therefore, partitioning is the most effective method to enhance performance on large dimension tables.

The error in merging data from Table 2 into Table 1 using last names could be due to discrepancies in spelling or data type between the two tables. It is essential to ensure that the last names are spelled consistently and that the data types are compatible for a successful merge. Option D suggests reviewing these aspects, which can potentially resolve the error, ensuring that each last name in Table 1 accurately corresponds to the same last name in Table 2, allowing for a successful data pull of addresses.
References: This answer is based on general data analytics practices and does not reference a specific document.

A dashboard with a scheduled delivery is an efficient way to provide a quick view of test performance. It allows for timely updates, which is crucial given that the superintendent needs the information promptly at the end of each month. The ability to filter scores by school enables the superintendent to easily segment and analyze the data as needed. Bar charts are effective for comparison and can visually communicate the performance across different schools or other categories, making it easier to identify trends and outliers at a glance.
References:
* Best practices in data visualization recommend using dashboards for real-time data monitoring and quick access to key metrics1.
* Guidelines for presenting performance data suggest that visual tools like bar charts are helpful in comparing and analyzing data effectively1.
* Educational performance data analysis often involves comparing scores across different schools or classrooms, which is facilitated by a well-designed dashboard2.