As Large Language Models (LLMs) advance, aligning them with human values is critical for their responsible development.Value principles serve as the foundation for clarifying alignment goals.Multiple sets of value principles have been proposed, such as HHH (helpful, honest, harmless) and instructions for data synthesis in reinforcement learning from AI feedback (RLAIF).However, most of them are heuristically crafted, without consideration of three primary challenges in practical LLM alignment: 1) Comprehensiveness to deal with diverse and even unforeseen scenarios in which LLMs could be applied; 2) Precision to provide LLMs with clear and actionable guidance in specific scenarios; and 3) Compatability to avoid internal contracts between principles.In this paper, we formalize quantitative metrics to evaluate value principles along the three desirable properties.Building on these metrics, we propose the Hierarchical Value Principle framework (HiVaP) 1 , which constructs a hierarchical principle set and retrieves principles tailored to each scenario in a cascading way, addressing above challenges.Experimental results validate that the three metrics capture the effectiveness of value principles for LLM alignment, and our HiVaP framework that enhances these metrics leads to superior alignment.

The recent surge in learned index algorithms, along-side traditional indexes, has greatly diversified indexing options to support query processing in databases. Despite the rapid expansion of learned indexes, there remains a significant gap in tools for index algorithm selection. Traditional research on index selection has largely focused on recommending which columns to index, as the choice between algorithms like B+tree or hash index was once straightforward. This was managed through basic rules or experiential judgment, given the historically limited options. However, this approach is inadequate today, due to the growing diversity and complexity of index algorithms. In this paper, we introduce a Learned INDex Algorithm Selector, LINDAS. Taking a learned approach, LINDAS uniquely focuses on automatically selecting the most suitable index algorithm for a specific column, that satisfies diverse performance objectives in a wide range of applications. We explore the design space of LINDAS, employing a carefully designed featurization approach to capture both data-and workload-specific characteristics with attention mechanisms, as well as the meta-features of index algorithms. Two variants of LINDAS are designed to cater to diverse scenarios and adapt readily to new datasets, workloads, and emerging index algorithms. Comprehensive evaluations of LINDAS across various datasets and workloads demonstrate its effectiveness and superiority compared to applicable baselines.

As modern applications generate data at an unprecedented speed and often require the querying/analysis of data spanning a large duration, it is crucial to develop indexing techniques that cater to larger-than-memory databases, where data reside on heterogeneous storage devices (such as memory and disk), and support fast data insertion and query processing. In this paper, we propose FILM, a F ully learned I ndex for L arger-than- M emory databases. FILM is a learned tree structure that uses simple approximation models to index data spanning different storage devices. Compared with existing techniques for larger-than-memory databases, such as anti-caching, FILM allows for more efficient query processing at significantly lower main-memory overhead. FILM is also designed to effectively address one of the bottlenecks in existing methods for indexing larger-than-memory databases that is caused by data swapping between memory and disk. More specifically, updating the LRU (for Least Recently Used) structure employed by existing methods for cold data identification (determining the data to be evicted to disk when the available memory runs out) often incurs significant delay to query processing. FILM takes a drastically different approach by proposing an adaptive LRU structure and piggybacking its update onto query processing with minimal overhead. We thoroughly study the performance of FILM and its components on a variety of datasets and workloads, and the experimental results demonstrate its superiority in improving query processing performance and reducing index storage overhead (by orders of magnitudes) compared with applicable baselines.

Sentiment analysis or opinion mining for subject information extraction from the text has become more and more dependent on natural language processing, especially for business and healthcare, since the online products and service reviews affect the consuming behaviors. Word embeddings that can map the words to low-dimensional vector representations have been widely used in natural language processing tasks. But the word embeddings based on context such as Word2Vec and GloVe fail to capture the sentiment information. Most of existing sentiment analysis methods incorporate emotional polarity (positive and negative) to improve the sentiment embeddings for the emotion classification. This article takes advantage of an emotional psychology model to learn the emotional embeddings in Chinese first. In order to combine the semantic space and an emotional space, we present two different purifying models from local (LPM) and global (GPM) perspectives based on Plutchik's wheel of emotions to add the emotional information into word vectors. The two models aim to improve the word vectors so that not only the semantically similar words but also the sentimentally similar words can be closer than before. The Plutchik's wheel of emotions model can give eight-dimensional vector for one word in emotional space that can capture more sentiment information than the binary polarity labels. The obvious advantage of the local purifying model is that it can be fit for any pretrained word embeddings. For the global purifying model, we can get the final emotional embeddings at once. These models have been extended to handle English texts. The experimental results on Chinese and English datasets show that our purifying model can improve the conventional word embeddings and some proposed sentiment embeddings for sentiment classification and multi-emotion classification.