private Collection<Tag> appendSearchableTags(LogData.Builder logData) {
        HashSet<Tag> logTags = new HashSet<>();
        logData.getTags().getDataList().forEach(tag -> {
            if (searchableTagKeys.contains(tag.getKey())) {
                final Tag logTag = new Tag(tag.getKey(), tag.getValue());
                if (tag.getValue().length()  > Tag.TAG_LENGTH || logTag.toString().length() > Tag.TAG_LENGTH) {
                    if (LOGGER.isDebugEnabled()) {
                        LOGGER.debug("Log tag : {} length > : {}, dropped", logTag, Tag.TAG_LENGTH);
                    }
                    return;
                }
                logTags.add(logTag);
            }
        });
        return logTags;
    }
RecordSinkListener forwards the log data to the persistence layer with the query required conditions.
oap-server/analyzer/log-analyzer/src/main/java/org/apache/skywalking/oap/log/analyzer/provider/log/listener/RecordSinkListener.java